Oxygen Sensors

There all screwed into the exhaust system / pipes. There about 4 inches long with an electric wire coming out of the top of them.

The code reading will be P1166 or P1167 for the primay "upper" oxygen sensor. It is recommended that both of these sensors be replaced every 100,000 miles even if there is no check engine light. There are two oxygens sensors on the 2002 Honda Accord as well as other years of this make of Honda. The "primary" oxygen sensor the (upper sensor, or the "upstream" sensor) is located under the hood in the exhaust manifold right on the front of the engine. It is easy to see and to reach. It is also usually easily removed. However, you may need to use a special wrench to remove either upper or lower sensor. I don't recommend trying to remove the sensors with a Cresent wrench. Most auto parts stores sell two kinds of O2 sensor removal wrenches. They cost around $10.00 for either kind. One type is a deep well socket with a slot cut up one side so the wire can come out. I don't particularly like this tool because it tends to open (spread) when you apply torque at the end that goes on the sensor. It has a tendency to slip and it may round off the corners of the sensor. If that happens you are in real trouble. I recommend a long, heavy duty 7/8" box wrench, with a slot cut in the box so you can get it on the sensor without cutting the wire connector. I choose not to use any type of penetrating oil when removing the sensors because it is reccommened that the tip of the sensor should never come in contact with any oil (even the oil on your fingers) So be extremely careful not to touch the end of the sensor. The sensors come with a plastic cover to protect the sensor from contact. Only remove this when you are ready to install it. DO NOT OIL OR GREASE THE THREADS. The lower sensor, sometimes called the "downstream" sensor is located in the catalytic converter, so it's a little more difficult to get to because it's on the underside of the car. You will probable need to raise the car on some safety stands to reach it comfortably. The catalytic converter resembles a muffler, but it is in front of the actual muffler. The catalytic converter will be slightly toward the passenger side of the vehicle. The sensor will be on your right side of the catalytic converter if you are looking at it from under the car and your head is toward the front of the car. It resembles the the upper sensor, if that helps you spot it. This one is sometimes very difficult to remove. You may have to put some support (blocks of wood, etc. ) under the catalytic converter so you can pull down hard on the wrench without pulling down hard on the catalytic converter and the exhaust system. After replacing the sensor/sensors take the vehicle to the nearest parts house that will reset the "check engine" light for free. Preferably the parts store that sold you the sensors. so if the light doesn't reset they may have sold you a defective sensor. I would take my 7/8" sensor wrench with me just in case. Any member feel free to edit and correct this answer if necessary.

Bank 1 is the side of the engine that includes cylinder #1. So it depends on the engine.

It or they are either screwed into the exhaust manifold(s) or exhaust pipe. The 1991 and 1992 4.0 L OHV engines have 1 oxygen sensor The 1993, 1994, and 1995 4.0 L OHV engines have 2 oxygen sensors The 1996 and newer 4.0 L OHV engines have 3 oxygen sensors The 1997 and newer 4.0 L SOHC engines have 4 oxygen sensors The oxygen sensors installed "upstream" before the catalytic convertor(s) are used for engine management The oxygen sensors installed "downstream" after the catalytic convertor(s) are called catalyst monitors and monitor the efficiency of the catalytic convertor(s)

There are two O2 sensors. One on the exhaust manifold and the other is on the exhaust after the catalytic converter.

The one on the manifold causes the most problems as it immediately affects fuel mixture being delivered to your engine.

www.trailvoy.com Trailblazer enthusiasts website!

The 2005 Ford Expedition 5.41 has two Oxygen Sensors that might need to be replaced at the same time. One is located in on the motor near the front of the catalytic convertor. The other O2 sensor is located behind the catalytic convertor. To change them, it is possible to manipulate the clips holding them in and remove them, then put the new ones in.

Any time you have to reset the ECM, all you have to do is disconnect the negative battery cable for about 15 seconds--if you've replaced the sensor--I just had to do that twice--the first one apparently was bad so I had to buy another one and now that fault is gone.

pipe tape on threads

there are 4. here is one of them Bank 2 sensor 1

http://inlinethumb15.webshots.com/4942/2695479270043892667S600x600Q85.jpg

In a Ford Explorer bank one is the passenger side of the engine ( V6 and V8 )

go to advace auto parts and they will rent u the tool. it looks like regular socket with a slit down the side of it for the wire. they dont charge u to rent tool. just hold a card or somthing of yours till u bring it back. i changed mine in there parking lot. o2 sensor is 40 - 50$

The oxygen sensor measures the oxygen content of the exhaust stream. Therefore it is always located in the exhaust system somewhere between the exhaust manifold ports and the catalytic converter. On all Fords that I have worked on the O2 sensor is located in the exhaust header on the passenger side of the vehicle usually very near the starter. Look on the underside of the vehicle, on the exhaust header, just behind the right front tire. You should see a cylindrical tube screwed into the header with a electrical lead attached.

If it is a Vortec it will be inside the tube running from the intake to the air filter it is a rubber hose with this stuck in it!

There are 4 sensors total. All are on the exhast pipes. 2 "upstream" are before the catalytic converter and 2 "downstream" after the catalytic converter.

There are two. They are on either side of the catalytic converter in the exhaust system.

There are 4 O2 sensors on my 1997 F-150. There are 2 just after the exhaust manifolds (one on either side of the engine). These two are visible in the engine bay but are easier to remove through the wheelwell after removing the splashguard. The other two are just after the catalytic converters, again one on either side. i'm assuming your check engine light is on and you had a diagnostics done. the bank 1 sensors are on the passenger side of the vehicle and bank 2 is drivers side, at least in my truck. in fords in general bank 1 is on the side of cylinder 1 in the firing order. sensor 1(upstream) is the ones in the engine bay and sensor 2 (downstream) is after the cats... hope this helps, i jus got done doing mine and i found that if sensor 1 goes that #2 tries to pick up the slack and it too will fail soon. its best to replace them in pairs on the same bank side

On a 2005 Ford F-150 :

( for the 4.2 liter V6 , 4.6 and 5.4 liter V8 engines )

Bank 1 is the passenger side of the engine

Sensor 2 is in the exhaust AFTER the catalytic converter

Don't know about the 4-cyl for certain, but the diagram of the 4-Cyl in my Haynes repair manual shows one exhaust manifold, so I'm guessing there would be one. The best way to determine this would be to examine the exhaust manifold. On my truck, this is easiest from below the car On my '94 6-Cyl there are two. They are located on the small end of the exhaust manifold. They can be most easily seen from underneath the truck near the transmission where the manifold connects to the exhaust. They look like a silver tube about 3" long sticking out of the manifold and have a 4 connector cable coming from the end.

open the hood look underneath of the air intake and you'll see the exhaust manifold and another you can see if you look behind the front driver side tire up toward the engine

Find very good instructions with photos at:

http://matrixowners.com/topic/72977-diy-how-to-change-an-oxygen-sensor-in-a-matrix/

I used them and they are easy to follow. Replacement time 15 minutes.

What is OBD, and what are its benefits? OBD stands for "on-board diagnostics," a computer-based system built into all model year (MY) 1996 and newer light-duty cars and trucks. OBD monitors the performance of some of the engines' major components, including individual emission controls. The system provides owners with an early warning of malfunctions by way of a dashboard "Check Engine" light (also known as a Malfunction Indicator Light or MIL, for short). By giving vehicle owners this early warning, OBD protects not only the environment but also consumers, identifying minor problems before they become major repair bills. How do I know the OBD system is working correctly? When you turn on the ignition, the "Service Engine Soon" or "Check Engine" light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the environment! What does it mean if the light turns on while I'm driving? If the light comes on and stays on, the OBD system has detected a problem. Your vehicle might have a condition that wastes fuel, shortens engine life, or causes excessive air pollution. If left unaddressed, these conditions could also damage your vehicle and lead to increasingly expensive repairs. For example, OBD can identify a loose or missing gas cap (which wastes fuel and contributes to smog) or engine misfire (which can lead to severe or permanent engine damage). What should I do if the light stays on? There is no cause for panic. The vehicle is just telling you to seek attention soon. When you reach your destination, make sure the gas cap is not loose or missing. Always turn off your engine when refueling. If the light does not go out after a few short trips following gas cap replacement or tightening, have your vehicle serviced by a qualified repair technician soon! Delaying assistance could lead to more expensive damage. What does it mean if the light is blinking? If the light is blinking, a severe engine problem such as a catalyst-damaging misfire is occurring and should be addressed as soon as possible. You can still drive safely, but should minimize your time on the road. Try not to drive the vehicle at high speed or with excess weight (such as towing or carrying heavy equipment).

That is the O2 sensor on the passenger side at the manifold. Bank 2= side of #2 cylinder and sensor 1= first sensor back. I would first check if there is a bad connection. Reset the computer and see if the code comes back. The O2 sensor is around $60 at most part stores.

Bank 2 is the drivers side of the engine and sensor 2 is in the exhaust after the

catalytic converter ( downstream )