Oxygen Sensors

Also called as the lambda sensor, an oxygen sensor measures the proportion of oxygen in liquid or gas. Scientists use this electronic device in measuring respiration or production of oxygen. Oxygen sensors are also used in automobiles.

5,236 Questions
Oxygen Sensors

Where are oxygen sensors located and what are the names - designations - Windstar?

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

* On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."

* On a V6 or V8 engine:

** the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."

** The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

There are 4 oxygen sensors on the Windstars They are divided into 2 banks of 2. Bank 1 is the for the rear 3 cylinders of the engine - Bank 2 is for the front 3 cylinders. Bank 1 / Sensor 1 (upstream) is located just below, in the pipe, the exhaust manifold on the back of the engine. REMOVE TIP: you may have to bend part of the transmission heat shield out of the way - be sure to put it back when done.

Bank 1 Sensor 2 (downstream) is located just past the drivers side catalytic converter. Bank 2 Sensor 1 (upstream) is located just below the exhaust manifold, in the pipe, at the front of the van - access is from the top. Bank 2 Sensor 2 (downstream) sensor is located just past the passenger side catalytic converter. NOTES: * Use lots of penetrating oil - allow to soak - to make removal easier and avoid damaging the exhaust pipe

* the sensors are screwed directly into the pipe at a 90 degree angle and look like spark plugs with either 8", 12", or 14" wires attached to them

* Tools:

* ** ** it is usually a 7/8ths size wrench ** special-purpose oxygen sensor socket - not expensive, and commonly offered for free use by the auto parts store

***

* Inspect the condition of wires and that they are not touching any parts of the exhaust system

* Before getting under the van, make sure to disconnect the battery if you have the Air leveling suspension

Rule of thumb: Bank 1 is on the side of the engine with cylinder #1 6 Cylinder numbering:

-----

1 2 3

4 5 6

----

Front of vehicle And before spending any $$ on replacing a sensor, I would test it to ensure it really really has failed! It's very likely someone read the DTC (diagnostic trouble codes) that cited an oxygen sensor reading - but then said something that leads you to believe it's a failed/bad sensor and needs replacing. The vast majority of times that is NOT the problem.

Take those codes and research them on the internet! (see "Related Links") A perfect example are P0171 and P0174 codes - indicate a lean mixture was read in bank 1 & 2 (respectively). On the Windstar, that's a prime symptom covered in Technical Service Bulletin TSB# 03-16-1 (see "Related Questions") The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach there are 3 oygen sensors on a 1999 ford windstar , one (1) is located on the exhaust pipe where it come down from the engine in front of the van, the second one is loated if front of the catalytic converter the 3rd and last one one is located at the back of the catalytic coverter. all three of them has different lenght of wire on them so besure you buy the right one. the prices starts around 39.95 each. i just replaced all three of mine i also have a 1999 ford windstar. good luck. ron if 02 and 97 are the same then the rear side is has cylinders 1-3 (therefore i assume this must be side 1) Also you can tell cylinder 1 is on the head that will be about 1 inch further to the front of the engine. Autozone.com has the oxygen sensor testing procedures.

See "Related Links" below No - you can replace only those that have failed or are triggering error codes. four i believe. There are two sensors, one located in the engine compartment just below the radiator on the manifold. Gently disconnect the wire connection then take a wrench and loosen the hex nut(similiar to removing a spark plug) by turning left or counter clock wise. If the enamel tip is yellow or black, it is worn. It should be white. The second one is located midway on the exhaust system behind the transmission. Same procedure. Sensor can be accessed behind the right front wheel, on the manifold/muffler assembly. Be careful as this area WILL be hot if you have driven the vehicle prior to changing the sensor. For better access, the wheel might have to be removed. REMOVAL & INSTALLATION See Figures 1, 2, 3 and 4

Fig. 1: Never detach the oxygen sensor connector while the engine is running

Fig. 2: An oxygen sensor wrench is available from Ford or aftermarket manufacturers to ease sensor removal

Fig. 3: If reinstalling an old oxygen sensor, coat the threads with anti-seize compound. New sensors are already coated

Fig. 4: Oxygen sensors are located in the dual converter Y-pipe ---- They mount into the twin catalytic converters, they're not exactly "pre-cat". I think there's one before and one after the cat con. It also may depend on engine size, 3.0 or 3.8 liter. There are four O2 sensors. Two are in each of the exhaust manifold lines coming from the two sides of the V6 engine. In each branch, one sensor is before the catalytic converter and one is at the output of the catalytic converter 4- 02 senors 2 up stream and 2 down stream Ummmmm.... Which one? There are 4 or 5 on those ones....

Two - located before and after the catalytic converter.






422423424
Emissions and Exhaust Systems
Oxygen Sensors
Pollution
Air Pollution

How has technology affected car pollution?

It has radically reduced the emmissions given off from automobiles. Too bad the big vehicles aren't as closely scrutinized yet.

It is absolutly amazing. From a seminar recently, I understand that leaving the fuel cap off will release more hydrocarbons than from the exhaust out the tail pipe.

With the addition of flex fuel, electric, propane, hydrogen, bio-diesel, and Hybrid cars the outlook is better.

I have found that since the advent of OBDII the number of problems that can occur is astronomicle. I have a pre-OBDII and an OBDII vehicles,and by comparison (Both being Fords) the OBDII has suffered more problems (From very low MPG to extremely bad performance issues not able to be corrected by Ford engineers themselves). At any given time the dealerships claim it is in the computer program to which they can not change(Poor MAF sensor performance,Timing issues)they just don't seem very knowledgeable about what they are doing or care about the matter (You already bought it tough luck is the usual answer).But their resolve to the delema was to go online and purchase a chip for socket J2 on the computer,I asked if the vehicle does not get 21M.P.G. like the manufacturer states than to me there must be a problem. After the techs laughed they stated that there is no possible way for that vehicle with that program to attain that fuel economy.It was stated that 18 M.P.G was the best I'd ever see. Not accepting this from Ford I set out on a little adventure, and discovered their big flaw. It was the catalytic converters, and by having four of them would be a strain on any engine. So we decided to test our theory,and removed the larger segments of converters (2 of them). Created a filler pipe to cover the distance, and re-inserted the O2 sensor as to not throw a code. Discovery was the fuel economy went from 18 M.P.G. to 26 M.P.G. This was a very large jump in fuel economy. To test this out I had to do it several times on over the road tests, and the results came out to within a few tenths of a M.P.G. of each other. So, in removing the technology and applying some old fashioned know how we were able to make the vehicle perform better and be more economical than the manufacturer could. (And by the way Ford blames the E.P.A. for their bad designs). JIM

310311312
Auto Parts and Repairs
Oxygen Sensors
Chevy Impala

Why does a catalytic converter go bad?

Because too old or get damaged

If an engine is not tuned properly and allowed to run continuously, it can damage the cat by overheating and melting the catalyst inside causing an air restriction. The inside of the cat can also break up into pieces causing again an air restriction.

293294295
Head Gaskets and Valve Covers
Oxygen Sensors

What is the function of oxygen analyzer?

it anylises oxygen durbrain

281282283
Oxygen Sensors
Marketing Advertising and Sales
Mice and Rats
Definitions

What does downstream presence mean?

down stream is water flowing into a larger body of water

281282283
Catalytic Converters
Oxygen Sensors
Mercury Sable
Ford Explorer XLT

Where are oxygen sensors located and what are the names - designations - Sable?

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

  • On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."
  • On a V6 or V8 engine:
    • the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."
    • The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

NOTES:

  • Use lots of penetrating oil - allow to soak - to make removal easier and avoid damaging the exhaust pipe
  • the sensors are screwed directly into the pipe at a 90 degree angle and look like spark plugs with either 8", 12", or 14" wires attached to them
  • Tools:
  • ** ** it is usually a 7/8ths size wrench
    • special-purpose oxygen sensor socket - not expensive, and commonly offered for free use by the auto parts store
  • Inspect the condition of wires and that they are not touching any parts of the exhaust system

NOTES:

Rule of thumb: Bank 1 is on the side of the engine with cylinder #1

6 Cylinder numbering:

-----

1 2 3

4 5 6

----

Front of vehicle

AnswerBank 1 is usually the engine side with the number one cylinder. As you have a 6 cylinder and front wheel drive, bank one is on the backside of the motor - meaning near the firewall/windshield. Sensor 1 is the sensor before the catalytic converter. Open the hood, follow the exhaust pipe from the motor towards the catalytic converter. The first sensor you come to is sensor one. Sensor 2 is after the catalytic converter. Bank 2 is the opposite side of the motor from bank 1 (obviously). CorrectionAlso see http://v8sho.com/SHO/TSB0197HO2SServiceTips.htm#fig1 Answer - EditorialAnd before spending any $$ on replacing a sensor, I would test it to ensure it really really has failed! It's very likely someone read the DTC (diagnostic trouble codes) that cited an oxygen sensor reading - but then said something that leads you to believe it's a failed/bad sensor and needs replacing. The vast majority of times that is NOT the problem.

Take those codes and research them on the internet! (see "Related Links")

A perfect example are P0171 and P0174 codes - indicate a lean mixture was read in bank 1 & 2 (respectively). On the Windstar, that's a prime symptom covered in Technical Service Bulletin TSB# 03-16-1 (see "Related Questions")

The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach

AnswerThey are screwed into the exaust system at various points. Some people say that there are 4 oxygen sensors, but technically,that is not correct. Only the front 2 are considered oxygen sensors. They are screwed into the exaust pipe, one on each bank,after the exaust manifold, but before the catalytic converter. Sometimes they are screwed directly into the exaust manfold itself.

The other 2 are actually called catalyst moniters. They are oxygen sensors, but they serve a different purpose. They moniter the activities of the catalytic converters, thus the name, catalyst moniters. They are screwed into the exaustone on each bank,after, or downstream, of the catalytic converters.They are all just typical 4 wire heated O2 sensors, nothing special about them. The EPA requires all cars sold in the US after 1996 have heated oxygen sensors.

AnswerAs far as I know the only place OXYGEN sensors are mounted are on the exaust system, either on the header pipe or after the cat-converter. Rarely are they located on the cat-converters themselves. Mostly they will have one electric wire connecting them to the computer but depending on the year and make the will have a two wire connection. I am not certain about the Sable's electrical wiring but the OXYGEN SENSERS postions for FORD/MERCURY are generally on the hot pipes. I hope this helps. Answercheck behind the pass side catalitic converter. (after) the unit. AnswerBank 1 is the front side of the motor (front of car), Bank 2 is the back side of car. (Bank one is actually associated with the number 1 cylinder which just so happens to be on the front of the car for the sable). Sensor 1 is before the catalytic converter, Sensor 2 is after the catalytic converter. Example, Bank 1, sensor 1. The sensor in the exhaust pipe for the front side of the motor before the catalytic converter. AnswerThe o2 sensor is in the exhaust manifold. It looks like a plug sticking out of the manifold and has 2 and sometimes 4 wires coming out of it. Hope this helps Don's Auto AnswerThey are screwed into the exaust system at various points. Some people say that there are 4 oxygen sensors, but technically,that is not correct. Only the front 2 are considered oxygen sensors. They are screwed into the exaust pipe, one on each bank,after the exaust manifold, but before the catalytic converter. Sometimes they are screwed directly into the exaust manfold itself. The other 2 are actually called catalyst moniters. They are oxygen sensors, but they serve a different purpose. They moniter the activities of the catalytic converters, thus the name, catalyst moniters. They are screwed into the exaustone on each bank,after, or downstream, of the catalytic converters. Answerthe oxygen sensors are on the exhaust pipes right before where it hooks into your manifolds. there are 2 of them. one for each manifold. AnswerGenrally the O2 sensor in most vehicles is located in the exhaust system. With the engine cool enough to touch, look at the front of your engine where the exhaust manifold is attached to the engine. The O2 sensor will be attached to the manifold or a little lower where the manifold joins into a single pipe. It will be the only electrical component attached to your exhaust system nearer to the engine. Never remove any nut, bolt, spark plug or sensor from a hot engine. Warping of the orifice may occur as it cools and now you have a bigger problem. If you must, then replace the part immediately.
263264265
Oxygen Sensors
Chevy Trucks and SUVs
Chevy Trailblazer

How do you cleaning oxygen sensor Chevy Trailblazer?

I cleaned one once,fully expecting to have to buy a new one, with a very fine wire brush and or steel wool and a little wax and grease remover on a rag. Ididn'thave to buy a new one. the check engine light went out and it ran fine. Hope this helps.

272273274
American Cars
Oxygen Sensors
Check Engine Light
Chevy Blazer S-10

Check engine light diagnostic test indicates bank 2 O2 sensor is slow to respond where is this sensor located?

just a quick note: bank 2 is LEFT side (drivers) on a rear wheel drive vehicle ,on front wheel drive vehicles it would be the front side when looking down from the front of the vehicle ,Sensor 2 is after the cat converter! if you replace that sensor, clear the codes or have someone clear them for you and you should be all set

Chris (technician for 20 years !!!!!)

Hey James==It would help if you stated what kind of car you have. Joe

the 2 of bank 2 is the 2nd oxygen sensor that is located after the catalytic converter.usually closer to the tailend of the header pipe.

The sensor I believe you are looking for is in the exhaust pipe or exhaust manifold, usually the right bank which is on the right side of the car (driver is left), or close to the firewall if engine is mounted sideways. Some cars are equipped with a sensor behind the catalytic converter that tells the computer the HEALTH of the converter only. It has nothing to do with running of the engine per say.

(Mechanic for 35 years)

Bank 1 is which ever side has cylinder 1. It could be left or right. Bank 2 would be the other side. Bank 1 sensor 1 would be before the catalytic converter. Bank 1 sensor 2 would be after the converter. The same applies with bank 2.

(mechanic for 12 years)

265266267
Fuel and Fuel Intake
Oxygen Sensors

What does an oxygen sensor do for a truck?

The computer uses the oxygen sensor reading from the exhaust to adjust the amount of fuel injected into the engine.

249250251
Transmissions and Drivetrains
Oxygen Sensors
Chevy Silverado
Ford Ranger XLT

Are there any sensors for your 4 wheel drive on the tranny that stop it from engaging?

It all depends on the year, and make of the vehicle, anything 1995 or newer can be reset by simply disconnecting the battery for about 15 minutes, if that does not work on chevys there is an inexpensive sensor that can be replaced located behind the kick panel of the passenger side. But I don't know of a universal fix all.

What kind of vehicle do you have, motor size etc.

It does depend on the vehicle but I am having the same problem with my '92 chev K1500 and have been told that there is a switch on the transfer case that activates an actuator on the front differential it may be one of those things or both

If it is an older style truck it is probably the cylanoid. that's what mine was anyways

217218219
Oxygen Sensors

Where does oxygen go after its inhaled?

i forgot

211212213
Oxygen Sensors
Ford Ranger
Honda Civic
Check Engine Light

Why does the check engine light come on and how do you reset it?

The "check engine light" is a warning light that is illuminated when there is a problem with the EMISSION SYSTEM only. Emission system being the pollution control system. It is a good thing once you understand it.

<><><>

The " check engine light" is also known as a malfunction indicator light (MIL). You can disconnect the battery red lead for about 5 min and it will reset. However, if there is a hard fault, it will come back on.

<><><>

Disconnecting the battery won't do the trick on OBD 2 vehicles.

<><><>

Without a scan tool designed to reset the electronic control module (ecm) a do-it-your-selfer can't reset the check engine light.

Pull the codes from the computer using an OBD (II) code reader. Match the code to the troubleshooting procedure, follow the procedure to find the source of the fault. After you have repaired the fault, the light will go out if that was the only problem. There are "monitors" or self tests the computer runs the car through a drive cycle, if a problem occurs, it may not run all of the self tests until that problem is taken care. Therefore, another problem may exist.

<><><>

One point that was brought up a a recent meeting of technicians was that the amount of hydrocarbons is greater when the gas cap is left off than when the engine is running. Hydrocarbons are part of pollution emitted as gasoline evaporates. Going a step farther, one facet of the emission system is the "Evaporative" portion. This is when the fumes from the gasoline are leaking from the system into the outside air. This is one part of the emission system that can trigger a check engine light. I would say that about 7% of the vehicles that have a check engine light are the result of a loose or inadequate gas cap.

But understand that many scenarios are possible with the "check engine light" The vehicle's powertrain computer (note that some vehicles have 17 different computers) will run a series of self-tests. They will only run under certain criteria and they can be vastly different from manufacturer to manufacturer. Some self-tests are not run until preceding ones have run successfully. So if there is a problem in one particular area that is preventing another self test from running, you can have a situation where one problem is fixed, but another still exists. If you fix a problem and drive the car through a drive cycle that sets the monitor (or self test) the light will go off as it passes that criteria that triggered it in the first place.

After 1996, the auto industry went to a idea called OBD II (On Board Diagnostics). This was to get all the manufacturers onto a similar plane for troubleshooting and powertrain control. While they still differ vastly, many corrections and adaptations were made for technicians to better fix the check engine light problems.

Prior to this there were so many different and poor troubleshooting data from a check engine light problem that resolving the problem was much more difficult.

Many early warning lights of this nature were set to illuminate based on mileage. An oxygen sensor was one of the things that was meant to be replaced when that mileage was hit. This is much like many current "Change oil lights" which are set up to come on after a pre-set mileage.

<><><>

Great question and good answer above. There is one thing to add however. On my 2004 Buick for example I am required to manually reset the "check oil" light myself every time I get an oil change. This ensures that the system understands the condition the oil is in. If/when I do not reset it, not long after my expected date the light goes on by default as a reminder.

Your instruction manual would outline this. Mine for example is simply...

1. Insert key

2. Turn key to ON, without engaging engine (just before the engine cranks, and leave key there)

3. When placed to ON, press and depress the brake slowly 5 times in 5 seconds.

4. Turn key to off.

5. Turn key and start engine.

The check engine light is now reset, if it returns shortly it is an actual issue, rather then a reminder.

<><><>

Some Ford Mondeos have a 'Service interval expired' warning light. It is pretty much the same as the "check oil" light mentioned in the answer above.

On that type of Ford Mondeo there is a small hole in the display screen in front of the 'Service interval expired' warning light. To reset it, just turn the ignition key until the all warning lights come on but do not start the engine. Then press a tiny button in the warning light display panel by poking a straightened metal paper clip through the hole. If you hold it steady for 10 seconds whilst keeping the ignition on, the warning light goes out. It will come on again when the service time period again expires.

203204205
Oxygen Sensors
Ford Explorer Sport
Ford Explorer XLT

Where are the oxygen sensors and how do you replace them on a 2004 cavalier?

On the exhaust manifold near the headpipe connection or on the headpipe near the exhaust manifold.

AnswerThere are 4 oxygen sensors (o2 sensors)and they are all located on the exhaust coming from the motor under the vehicle by the catylac converters. AnswerO2 sensors are on the exaust manifold under the vehicle AnswerThere are 4 sensors, though not all of them are technically called "oxygen sensors. There are two that are upstream of the catalytic converters, one on each bank. Then, there are two more, one after each catalytic converter, that are oxygen sensors, but officially they are called catalyst monitors, because that is the job they are assigned to do.

To recap, the two before the cats (or upstream), are oxygen sensors, and the two after the cats (or downstream) are catalyst moniters. Although all 4 of them are oxygen sensors, their titles are different.

AnswerThere are 2 locations: one in between the catalytic converter and the manifold, the other is after the catalytic converter. The number of sensors varies with the engine type. The 4.0L v6 OHV has one sensor in each location, the 4.0L v6 SOHC has two sensors on the manifold side. AnswerWell, with my 4.0L SOHC motor, there are FOUR O2 Sensors, two aft and two forward of the catalytic convertor. The two forward ones are rather hard to access, but the two aft ones (located just to the right of the transfer case) are somewhat easier. They almost look like a spark plug with a wire and a clip coming out the back. AnswerDepending on the year, Ford Explorers may have one, two, or four Oxygen sensors (O2S). Earlier models have only one upstream sensor in the common exhaust header. Later models either have one upstream and one downstream (past the catalytic converter), or two upstream and two downstream sensors. It should be noted that although all of the sensors signals are monitored, it is the upstream sensors that affect the PCM.

It is far easier to do this on a lift and with small hands.

Simply access the sensors from under the vehicle. Detach the wiring harness. Using the appropraite sized wrench, unscrew the sensor. Reverse the process to reinstall.

Hint: A small pointed tool may help reach the passenger side upper most sensor wire harness.

AnswerThey are screwed into the exaust system at various points. Some people say that there are 4 oxygen sensors, but technically,that is not correct. Only the front 2 are considered oxygen sensors. They are screwed into the exaust pipe, one on each bank,after the exaust manifold, but before the catalytic converter. Sometimes they are screwed directly into the exaust manfold itself. The other 2 are actually called catalyst moniters. They are oxygen sensors, but they serve a different purpose. They moniter the activities of the catalytic converters, thus the name, catalyst moniters. They are screwed into the exaustone on each bank,after, or downstream, of the catalytic converters.

There is only 1 Oxygen (02) sensor on a 1991 vehicle. Beginning in 1996 (and some late 1995's), with the new OBDII system there were 2 sensors installed, 1 in front of the catalytic convertor and 1 behind the convertor.

Replacing 1996 Explorer oxygen sensorsThe oxygen (O2) sensors are located in the exhaust system. There are three sensors, one in each of the exhaust headers near each of the front wheels and the third in the common exhaust pipe further back. A special deep socket is available from any parts store to remove the sensors. The socket has a slit down its length to accomodate the sensor wire permanently attached. Simply disconnect the bullet connector and unscrew the sensor.

A few words of advice: 1. Be very careful around a hot exhaust system; wait for the pipes to cool down a bit, 2. WEAR SAFETY GLASES; there is a lot of metal that flakes off the exhaust system every time you touch it, 3. The sensors are best reached from under the car; be sure to use jack stands to properly support the vehicle,

Answerit is located on your exaust manifold under the vehicleIt's likely there will be one for each head on six's and eight's just before were the "Y" pipe meets the exhaust manifolds, another just before the catalytic converter and yet another after the converter.This doesn't mean you 4, but it's possible. AnswerAs I understand it, Bank 2 should indicate driver side, and sensor 1 should be the sensor closest to the front of the car, upstream of the catalytic converter. The safest way to find out for sure, is to find an honest Ford service technician and ask! Good luck AnswerHere is the oxygen sensor, and their location designations explained:They are screwed into the exaust system at various points. Some people say that there are 4 oxygen sensors, but technically,that is not correct. Only the front 2 are considered oxygen sensors. They are screwed into the exaust pipe, one on each bank,after the exaust manifold, but before the catalytic converter. Sometimes they are screwed directly into the exaust manfold itself. The other 2 are actually called catalyst moniters. They are oxygen sensors, but they serve a different purpose. They moniter the activities of the catalytic converters, thus the name, catalyst moniters. They are screwed into the exaustone on each bank,after, or downstream, of the catalytic converters. On a 4 cyl engine, there are only a total of two such sensors,the one in front of the catalytic convertor is the O2 sensor, the one behind the cat is the catalyst moniter. The location names for them are as follows: On a 4 cyl, the front is called "bank 1 sensor 1" and the rear sensor is called "bank 1, sensor 2." On a V6 or V8 engine, the passenger's side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward sensor on that bank would be "bank 1, sensor 1." The driver's side bank(forward mount engine), or front bank(transverse engine) would be bank number 2, thus the forward sensor on that bank would be "bank 2, sensor 1," and the rearmost sensor on that bank would be "bank 2, sensor 2." AnswerThere will be either 2 or 3 oxygen sensors. One sensor is in the header and one (or two) are "Post" catalytic converter. Most of the late model Ford V6 engines contain 3 sensors. These are screwed into the header and into you exaust pipe. This is a very easy and quick project. All of the sensors should be easy to locate. They stick out of you header and exaust pipe about 1.5 - 2 inchs. Just unscrew, unsnap from the wire harness and reverse this process with the new sensors. You should unconnect the battery during this process, this will also reset you check engine light. Goodluck.
207208209
Cars & Vehicles
Carburetors
Oxygen Sensors
Late Model 1979-New Ford Mustangs

What are the possible reasons a car could be idling high?

Hey Shelly==It could be many things depending on the make, madel and engine you have.Goodlluck Joe

Always check for vacuum leaks first. If it has a carburetor it is probably time for a tune. check for a stuck or damaged throttle cable. If it is fuel injected you may have a malfunctioning sensor or actuator somewhere. This will usually trigger a check engine light.

Another : Check the A.I.S. (Automatic Idle control) which could be sticking, or the passageways dirty, or defective or worn out. Other than vacuum leaks, AIS or Throttle Position Sensor (TPS), there can be wiring problems or crankshaft position sensors giving false or weak signals.

In older carburetted engines, check the cold idle mechanisms operation and adjustments, like the bimetallic spring actuator or its plumbing, even the inlet manifold could have some heating passages blocked. amclaussen.WOW! depends on the year and make if fuel injected it can be a throttle position sensor(TPS),IAC idle speed control sensor,throttle linkage,YOUR BIG TOE IS ON THE ACCELERATOR

183184185
Oxygen Sensors
Ford Escape

Where is the oxygen sensor on a 2006 Ford Escape?

I believe on your exhaust

180181182
American Cars
Catalytic Converters
Oxygen Sensors

Where are oxygen sensors located and what are the names - designations - Taurus?

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

  • On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."
  • On a V6 or V8 engine:
    • the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."
    • The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

NOTES:

  • Use lots of penetrating oil - allow to soak - to make removal easier and avoid damaging the exhaust pipe
  • the sensors are screwed directly into the pipe at a 90 degree angle and look like spark plugs with either 8", 12", or 14" wires attached to them
  • Tools:
  • ** ** it is usually a 7/8ths size wrench
    • special-purpose oxygen sensor socket - not expensive, and commonly offered for free use by the auto parts store
  • Inspect the condition of wires and that they are not touching any parts of the exhaust system
  • No special tool is required if you are not reusing the old sensor. Simply unplug sensor harness from vehicle harness then snip off the wires at the sensor. This will allow you to slip a 7/8" box wrench over the sensor for a tight, no slip grip for removal. Use the 7/8" open end wrench for installation of the new one.

NOTES:

Rule of thumb: Bank 1 is on the side of the engine with cylinder #1

6 Cylinder numbering:

-----

1 2 3

4 5 6

----

Front of vehicle

Answer - EditorialAnd before spending any $$ on replacing a sensor, I would test it to ensure it really really has failed! It's very likely someone read the DTC (diagnostic trouble codes) that cited an oxygen sensor reading - but then said something that leads you to believe it's a failed/bad sensor and needs replacing. The vast majority of times that is NOT the problem.

Take those codes and research them on the internet! (see "Related Links")

A perfect example are P0171 and P0174 codes - indicate a lean mixture was read in bank 1 & 2 (respectively). On the Windstar, that's a prime symptom covered in Technical Service Bulletin TSB# 03-16-1 (see "Related Questions")

The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach

There are 4 O2 sensors on your Taurus. 1 is under each exhaust manifold and there are 2 just before the Y pipe. If it shows no. 2 on the scanner it is on the front side near the radiator. If it shows no. 1 it is near the fire wall - the side of the engine with cylinder #1. 3 and 4 are located just before Y pipe but I don't know which one is which. its located on the right hand side of the engine when you are facing forward with the hood up its located in the lower right hand corner Under hood, center, lower engine area, front side of engine, mounted in exhaust pipe .

Oxygen sensors are always screwed into the exhaust manifold as they sense the amount of oxygen in the exhaust and tell the computer how to mix the air fuel ratio. More or less.

just in front of the cat converter.. on each pipe... There are four (4)oxygen sensors on the 96 Taurus the two in the back are screwed into the tailpipe on both sides of the Catalytic converter. They are on the top of the pipe so hard to see, but you'll see the wires coming off them. The other two are at the front of the engine. the sensors are located on the upstream and down stream of the exhaust system..one under the car behind the catalytic converter and one just in front at the top of the exhaust system comming out of the engine block.where is #1 sensor located ?

169170171
Oxygen Sensors
Welding and Cutting

What color is the oxygen tank for welding?

oxygen tanks are usually green in the united states, however, no standard is adhered to uniformly.

167168169
Fuel and Fuel Intake
Oxygen Sensors
Ford Taurus

Where is the O2 sensor on a Ford Taurus and can a backyard mechanic replace it?

144145146
Oxygen Sensors
Ford Contour

How do you replace an O2 sensor on your 1999 Ford Contour?

very easy its best to have the socket for an o2 sensor it has a slit down the side to allow for the wire to come out the side available at any auto parts store then you will find it in the front of the engine right behind the radiator it will have 4 wires coming out of it all you do is follow the wires to the wiring harness the detach the clip. then you use the socket to lossen it then unscrew the rest of the way out at this point wheather you bought one with the clip on it that attaches to the factory harness or if it has bare ends on the wires you may need to splice the wires to the original clip then screw it in place and your done 30 minutes tops

If you are talking about the 2.5 V6, then it's not as easy. According to several sources I've looked at while venturing to do this myself, there is debate among the experts, including Ford, Mercury, Autozone, Pep-Boys, Bosh website, Autoparts website and the toothless mechanic standing next to me in the Autozone checkout lane.

I think there are 4. I have found, and replaced 3 of the 4, and the fourth one, or AKA Bank-1 Upstream HO2, is between the firewall and the engine. The guys at the Mercury parts desk say that it's not really an O2, rather a catalytic sensor (Whiskey Tango Foxtrot).

Advice - Get Autozone to run a free diagnostic and tell you exactly which one it is, and replace only that one. I allowed my daughter to manage this thus I got the "Daddy, they're all bad" answer. Of course, being a good pop, I set my brain aside, believed what she said, spent $150 more than I had to, and found a different problem. You might be thinking about now, why would I listen to this person who got suckered by a teen-ager. Well, I'm just sharing something that will maybe help. I don't recommend the Hayne's manual either - it's pretty confusing. The Autozone freebie, so far, is better.

Semper Gumby

Oh - me again, the DA. The funky wrench the previous guy mentioned is a waste on the V6. Just use a (7/8) wrench. However, I may later learn that the funky wrench is the only way to get to the mystery O2. If so, I'll eat crow.

This is specific to the 1995 v6 model (and any other model years that may be identical to it as far as O2 sensors are concerned). The front bank sensor is relatively easy to do with a normal wrench. The rear is another matter as you can only access it from above. At the very least, you will have to remove the rear bank spark plug wires (better ID them with masking tape?) and the ignition coil (not hard). There is a metal track that provides support to a loom of wiring which traverses the engine from side to side, attached to the rear of the engine and close to the fire-wall. Only two small nuts hold that on, but you will have to use some force to remove the mounting tangs of this track off of the studs it is attached to. I was offered the loan of a modifed wrench for the sensor so I used it (the proper socket may have been a better option if you're willing to make the investment, but I don't hope to ever be able to make the comparison). As for the wrench, get a cheap 7/8 combination wrench and cut it down to no more than what you need to fit your hand, keeping in mind you are going to need the box-end of it. Grind over the cut off end to eliminate any sharp edges. Locate the sensor by hand (your eyes won't help here) and follow the wire up to the connector. Disconnect the sensor and hang on to the wire, placing the box end of your wrench over the wire. Follow it down onto the sensor and get the wrench over the sensor nut in such a way that you are going to be able to loosen it. If memory serves, you'll be pushing down to loosen. Once you have cracked it loose and maybe went through a couple more wrench-arcs, it should turn out by hand. Expect to spend about an hour replacing the back one. You might be tempted to do only the front if an engine fault code indicates the problem is the front one, but these are considered normal maintenance items, and you will be doing the rear at some point if you keep the car. .

155156157
Oxygen Sensors
Ford Trucks and SUVs
Ford Explorer XLT
Ford F-150

Where is oxygen sensor on a 1988 2.9 liter Ford engine?

The oxygen sensor on the 1988 ford 2.9 liter engine is located on the exhaust pipe just behind the right exhaust manifold. It screws into the exhaust pipe and has a small wire running to the tip of it. Just unplug the wire and turn out the sensor with a wrench.

147148149
Auto Parts and Repairs
Oxygen Sensors
GMC Jimmy

Where is the oxygen sensor on a 2000 GMC Jimmy?

There are several and they are all mounted on the exhaust system.

141142143
Catalytic Converters
Oxygen Sensors

How do you get into Buying and Selling Scrap Catalytic converters?

Check this site out! They have a book that tells your how to buy Scrap Catalytic Converter! The book even has a list of buyer in all 50 states and over 350 pictures with detailed descriptions and a lot more. Click the link.

135136137
Car Computers and Sensors
Oxygen Sensors
Mercury Grand Marquis
Pontiac Grand Prix
Grand Am SE

Where is the oxygen sensor on a 1996 Mercury Grand Marquis 4.6L?

On a 1996 Grand Marquis there are 4 oxygen sensors. 2 (1 on each bank) are mounted before the front catalysts near the manifold-->cat-pipe flange. These are the HEGOS or Heated Exhaust Gas Oxygen Sensor. These are the primary o2s and are what help the PCM determine the correct A/F ratio. There are another 2 directly after the fisrt set (1 on each bank) of catalysts moutned on the exhaust piping between the two catalysts on each bank. The primary goal of these is to monitor the catalysts' effieceincy. In summary: 4 o2 sensors in all 2 are the upstream/HEGOS o2s 2 the downstream o2s 4 cat-convertors in all

133134135
Cars & Vehicles
Emissions and Exhaust Systems
Oxygen Sensors

Why would a car smoke when it idles?

I am no mechanic but with my problems with my car all everybody told me is there are several things you can do to stop it:

Get a fuel injection flush.

You have a lot of carbon build-up, try getting your car on the open highway. What you will be doing is blowing all the old carbon out and it should run better after that.

Your car might be getting too much gas at idle, OR your oil pump isn't working correctly. Which means the pump is putting too much oil to the cylinders when you idle.

Worn Valve guides (seals) cause an engine to smoke at idle, when the vacuum is strong enough to pull oil past the worn seals. Generally, the smoke will be bluish and will billow out when taking off after idling. I also have the same problem & I think it's my oil rings

138139140
Car Computers and Sensors
Oxygen Sensors
Plymouth Voyager
Pontiac Sunfire
Honda Accord EX

Where is the Oxygen Sensor on a '94 Plymouth Voyager and how do you change it?

Hey Mario==It will be close to the exhaust flange and on some cars it is in the exhaust manifold. GoodluckJoe

132133134

Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.