Oxygen Sensors

This takes a little effort but it can be done with a volt meter. Typically they measure this with the repair computers in the dealerships and such. For a single wire sensor trace the wire color back into the cars computer. The computer is usually under a seat, passenger side dash or under the console. To make sure you traced the right wire disconnect the o2 sensor and using the connector end (of the wiring harness NOT the o2 sensor)use your meter and "ohm out" the wire ie check connectivity. On the computer side the harness connector will hopefully be the typical molex connectors that you can press your probe into from the outside. (Do not disconnect from the computer it wont start!).

Now that you know which wire into the computer comes from the o2 sensor, reconnect the o2 sensor and warm up your car. You may consider leaving the voltmeter probe in the molex connector before starting if you are concerned about poking around after it is running. In the volts setting (0-2 or 0-5 volts) leave the positive lead in the connector and the negetive lead to ground (usually anything metal connected to the frame). When you first start your car your numbers will be low 0.1-0.3 volts as this is a rich mixture necessary until the car warms up. Once warm expect numbers in the mid to high range. meaning 0.5 to 0.8 volts. If you bounce the throttle you will see a cyclic response from low to high 0.3 then 0.8 or so as the engine emits its exhaust. Consult your specific auto manual for acceptable ranges.

It is usually between 0 an 1 volt with 0 = rich and 1 equal to lean. Your auto manual should give you outputs for idle, and possibly under load (driving at a constant rpm)

If you have a multi wire sensor the same applies but you have to fish out the "signal" wire coming from the sensor. The other wires are typically for heating the sensor.

... I have done it myself on several cars but I don't know what they all look like and behave like so use this only as one data point.

I am not a mechanic but I know just enough from personal experience to say this much: I own a 1992 Volkswagen Jetta GL (gasoline). When the oxygen sensor goes bad on this car, the results are predicatable and consistent: it is always hard to start after sitting parked overnight or for several hours (say 8 hours). Instead of taking approximately 2 seconds to start the engine, it would now require approximately 8 to 10 seconds (up to 15 seconds) to start the engine. It is also my understanding that a bad oxygen sensor will also contribute to the destruction of the catalytic converter, requiring replacement of that part. What if the oxygen sensor is manually disconnected? Yes, this can be done. The results on my car is gas mileage is reduced from a peak of 33 mpg (highway/city) to about 28 or 29 mpg (ditto). The performance of the car is not affected but there is a noticeable but slight odor of fuel or oil when it is running cold. A disconnected oxygen sensor immediately resolves the hard starting problem (assuming all other parts are functioning to spec). Beyond that, I could not advise you on what would be, if any, the long term performance consequences of running around with a disconnecteed oxygen sensor. This is only my experience and only with this type of car.

1) Check you're owners manual for fuse locations!

2)A new starter does not turn engine???

- Check fuel

- Check for spark

- Check battery 1) Check you're owners manual for fuse locations!

2)A new starter does not turn engine???

- Check fuel

- Check for spark

- Check battery

There are 2 different O2 sensors on a 2000 accord, the first will be on the actual exhaust manifold itself, and the other is going to be under the car, either made into, or right after the catalytic converter. If you have a diagnostic (check engine light)code that says "Bank 1, Sensor 1" it's going to be the one on the manifold; if it says "Bank 1, Sensor 2" it's the one right after the catalytic converter.

It is for vacuum storage. It keeps blower mode from switching to defrost when accelerating. The mode selection is vac controlled and will default to defrost when vac is lost or low. This stored vacuum keeps that from happening

I have a 2004 honda the engine light has been on for a while, I have had it check out and they said they thought the sensor was just giving a bad code. I went to start it today and it wont start. wants to but wont. I checked the oil even though its just at 3,000 mile to be changed and it was so low.

A faulty O2 sensor will not cause a no start condition. I will cause loss of power and poor fuel mileage. You need to take your Honda to a professional who can diagnose your problem and not guess at what is wrong.

above the exhaust pipe entering the catalyst converter, Use an 11/16 wrench to loosen original sensor. above the exhaust pipe entering the catalyst converter, Use an 11/16 wrench to loosen original sensor.

You need to clean the connection where the ground is faulty. Start at the battery. Take off the cable wire brush the battery and cable then spray with some white lithium grease to prevent futher problems.

The HO2S Bank 1 Sensor 1 is located on the exhaust manifold nearest to the front of the car. The Bank 1 Sensor 2 is located on the exhaust pipe before the catalytic converter and after the pipe from the bank 1 and bank 2 exhaust manifolds meet.

On the 1.1, it's screwed into the exhaust pipe near the engine, and has a plug/socket connection on top of the tyransmission. The Haynes manual shows it and tells you how to change it.

Cost approx �63.00 from Motormania

you must also buy a lambda 22mm 3/8 socket to get it of,you can not clean them either

hey dude call up advance auto parts and give them the code and they will look the code number up in the book. i know it because i work there and use the book everyday. goodluck Answer

I own an 89 Dodge Dakota and from my experiences and research the reason that the check engine light does not stay on is because it goes into what is called a "limp in mode" which helps get you to a service station. If you have a Haynes manual or can get one, foudn at NAPA and Advacned Auto, you can look up the code fairly easy. I know that on mine the check engine light has never stayed on but the computer stores the code until it is cleared. I hope I have been helpful.

1999 Pathfinder: I had the computer checked 3 times. But no code was identified that pointed to any specific problem. Each reset caused the light to go away for different periods of time. Anywhere from 2 weeks to 4 weeks. Once it even went on and off within several days on its own. Best guess was emmissions, fuel, or loose connection on something. The car runs fine with no other symptoms. The light has been on now for 2 weeks. I'll reset again, have my mecahnic look over the engine, and see what happens. My 2000 Pathfinder has run with the check engine light on since 20,000 miles I now have 149,000 miles. It started when I changed the air filter to a K&N. My local mechanic has checked it numerous times and the computer shows no problems. You may want to check the air filter. I also own a 2002 Pathfinder the check engine light came on due to the seal on the fuel cap not making a proper seal. I replaced the seal and the light reset and has not come back on in a year.

Ther are two oxygen sensors on the system. One is located at the exhaust manifold and the other just after the Cat. There are several reasons why you may get these codes and at $100 per sensor you do not want to be wrong. If you are destroying a sensor then you should find out why before replacing it.

The purpose of a oxygen sensor is to monitor emissions.

it does this by detecting the air fuel ratio if to much air it Will tell computer to add more fuel if to much fuel it will tell computer to add more air

will help slightly with performance major with MPG and who cares about emissions right?

bad o2 sensor on left bank

Exhaust system. Usually manifold near port(s).

Downstream O2s are on the outlet side of the catalytic converter(s).

There are four oxygen sensors on the 1997 Chrysler LHS. 2 before the catalytic converter and 2 after.

There is an oxygen sensor right on the exhaust manifold, directly behind the radiator and fan. Follow the spark plug wires down from the top of the motor. From where those wires plug into the coils, go left (assuming you're standing in front of the car ;P). The sensor is the cigar chaped white thing that screws into the exhaust manifold with one wire coming out of it. There may be a second sensor (somewhere "under" the car), some cars have them, not sure about the SL series. Yes, the 99 Saturn SL2 DOHC does have a 2nd O2 sensor, I believe it is located under the car, mounted to the exhaust, after the caddy.

i just LEARNED THAT THERE ARE TWO O2 CENSORS ON A 99' FORD ESCORT THEY ARE EASY TO CHANGE. ONE IS RIGHT BELOW THE CAD CONVERTER AND THE SECOND ONE IS LOCATED ON THE MANIFOLD. JUST DISSCONNECT THE WIRES AND UNSCREW THE O2 CENSOR. THEN REPLACE IT.

It has one O@ sensor and one catalyst moniter(downstream O2 sensor). They are both on the exaust system. One is in the front of the eaust manifold which is bolted to the front of the engine, and one is further down screwd into the exaust system, after the catalytic converter.

I just cleaned both on my explorer sport 02. One is located under the drivers side where the exhaust hooks to the manifold and the other is on the passenger side. The one on the drivers side was easy cause i just laid under the car. the passenger side I had to turn the tire all the way to the left and snap off the guard on the wheel well to get to it. I used a 7/8" wrench and took them out and then sprayed brake cleaner on them to get the exhaust build up out and re-installed them. Then I removed the negative battery cable for 5 minutes to clear the check engine light and fixed the problem without having to buy a new o2 sensor.