How to Replace an Oxygen Sensor on Chevrolet Cars

by Contributing Writer; Updated June 12, 2017

The oxygen sensor or sensors on your Chevrolet car vehicle are not difficult to replace once you unscrew the units. Yet, since they ride on the exhaust pipes, the sensors' threads tend to seize to the pipes, making it difficult and dangerous to remove if you are not careful. We recommend the use of penetrating oil a few hours ahead of the job, if necessary. This will not only make your job easier but will help you avoid damaging the mounting threads on the pipes and costly repairs. Once you have the exact replacement for your particular Chevrolet car model, follow these steps to install them.

Under The Hood:

 How to Replace an Oxygen Sensor on a 2002 Silverado

Locate the oxygen sensor you wish to replace. This can be done by beginning at the exhaust pipe at the rear of the Silverado and following it up toward the front of the truck. The 2002 Chevy Silverado actually has two oxygen sensors--unless the truck has been outfitted with a dual-exhaust, in which case it will have four, two identical sets on each exhaust system. These oxygen sensors are located on the exhaust manifold immediately before and just after the catalytic converter--the large boxy part attached to your exhaust manifold. The oxygen sensors will look like fat, round pegs with a cluster of wires coming out of the tips.

Follow the wires coming from the oxygen sensor's tip until you find where it connects into the Silverado's wiring harness. Unplug the sensor's wire from the harness, taking care not to damage the electrical connector on the truck itself.

Use your wrench or ratchet and socket--the ratchet and socket is generally the preferred method--to loosen and unscrew the sensor from the Silverado's exhaust manifold. You may need to exert substantial force to do this, as oxygen sensors often become stuck or "frozen" in place due to their being constantly exposed to high temperatures. You are free to discard the sensor once you've gotten it out.

Coat the screw threads of the new oxygen sensor with an anti-seize compound of your choice. This is both to ensure a smooth installation, and also to make it easier to remove the sensor when the time comes to replace it.

Screw the new sensor into the exhaust manifold and tighten it securely. Once this is done, plug the sensor's wires back into the Silverado's wiring harness via the electrical connector mentioned in Step 2.

Repeat steps 2-5 for the remaining oxygen sensors as necessary.

Items you will need

  • Replacement oxygen sensor

  • Ratchet or 22mm wrench

  • 22mm socket or "oxygen sensor" socket

  • Anti-seize compound

 How to Replace the Oxygen Sensor on a 2000 Chevy Impala

Locate the oxygen sensor. The 2000 Chevy Impala has two of them, immediately behind and just in front of the catalytic converter on the exhaust manifold. Look for an object that appears to be a golden or brass peg with wires coming out of the tip.

Disconnect the wires that run from the O2 sensor into the Chevy's electrical system from the electrical socket on your car. Take care; damaging the electrical socket may cause the new O2 sensor to not draw power correctly.

Use a ratchet and 22 mm socket (or a 22 mm wrench) to unscrew the O2 sensor from where it is mounted on the exhaust manifold. You may need to use significant force, as the O2 sensor's location on the manifold, near the high heat and proximity to your car's emissions, often causes the sensor to get stuck.

Coat the threads of the new O2 sensor with WD-40 or a similar lubricant, then do the same to the threads in the hole where you just removed the old sensor.

Screw in the new O2 sensor and tighten it securely in place on the Impala. Plug the new sensor's wires back into the electrical system via the socket.

Items you will need

  • Ratchet

  • 22 mm socket or oxygen sensor socket

  • Lubricant

  • Replacement O2 sensor

 How to Replace an Oxygen Sensor in a Chevrolet Prizm

Replacing Bank 1 Sensor 1

Locate this sensor at the front exhaust pipe, right next to the exhaust manifold at the front of your Chevy Prizm.

Unplug the sensor electrical connector.

Unscrew the two sensor mounting nuts and discard the gasket. You can use a ratchet and socket to remove the mounting nuts.

Apply a light coat of anti-seize compound to the threads of the new sensor. Be careful not to touch the tip of the sensor with the compound or you may ruin the unit.

Start the oxygen sensor by hand, then tighten the sensor with the ratchet and socket but do not over-tighten.

Plug the sensor electrical connector.

Bank 1 Sensor 2

Remove the scuff plate located at the bottom of the driver's door frame, using a Phillips screwdriver.

Remove the left kick panel on the driver's side using the Phillips screwdriver.

Take the floor board insulator off the lower steering column using the Phillips screwdriver.

Locate the oxygen sensor electrical connector underneath the board insulator and unplug it.

Pull the sensor wire grommet out of the floor board, and then push the grommet and oxygen sensor harness through the floor board.

Raise the front of your Chevy Prizm using a floor jack and support it using two jack stands.

Locate the oxygen sensor at the back exhaust pipe, next to the back of the catalytic converter.

Disconnect the oxygen sensor from the exhaust pipe using an oxygen sensor socket and a ratchet.

Apply a light coat of anti-seize compound to the new sensor threads, but be careful not to touch the tip of the sensor with the compound to avoid damage to the sensor.

Start the sensor by hand on the exhaust pipe. Then tighten the sensor using the sensor socket and ratchet but do not over-tighten.

Detach the sensor wire grommet from the old unit and install it on the new sensor.

Push the sensor harness and grommet through the floor board.

Install the wire grommet on the floor board and plug the sensor electrical connector.

Install the floor board insulator on the lower steering column using the Phillips screwdriver.

Mount the left kick panel on the driver's side using the Phillips screwdriver.

Attach the scuff plate to the bottom of the driver's door frame using the Phillips screwdriver.

Items you will need

  • Ratchet and socket Anti-seize compound Phillips screwdriver Floor jack and 2 jack stands Oxygen sensor socket

 How to Replace the Oxygen Sensor on a Blazer

Determine which oxygen sensor needs to be replaced. This can be done with a code reader and there are many repair shops that will check your codes for no charge. The code reader should indicate which oxygen sensor is giving the trouble code. Determining which sensor is bad will be the most challenging part of this job. On Blazers manufactured after 1999, there will be multiple banks and sensors. The bank closest to cylinder one is bank one, so finding where the number one spark plug in the engine could help you determine which side. The higher the number the sensor, there further back in the exhaust system it is placed. For example Bank One/Sensor One would be the closest sensor to the manifold on the cylinder one side. After the front Y-pipe on the exhaust system for the Blazer, it channels into a single exhaust before it streams through the catalytic converter. Some parts stores will have code readers and if you buy the oxygen sensor from them, then they will have a vested interest in helping you find out the information you need and sell you the proper sensor for replacement. Also, check the sensor before you leave to be sure there is a small amount of anti-seize compound on the threads. If not, purchase a small tube of it at the parts store as well. Most quality sensors come with there perfect amount already coated on the threads of the new sensor.

Raise the front of the vehicle on a flat, level surface. It is recommended to use car ramps for this, but you could use a floor jack and two jack stands to elevate the front. Just be sure the vehicle is secure and safe because you're going to be underneath it. Place the Blazer in park or gear and apply the parking brake. Turn off the ignition and remove the keys so no one turns it on by accident while you're underneath. Place a wheel chock behind one rear tire.

Crawl under the vehicle keeping the remaining hand tools handy so you can reach them as needed, including the replacement sensor. and examine the exhaust system. Use a creeper if you have one. Once you've found the sensor you're looking for, follow the wire coming out of it and trace it with your hands to feel where the plug is for it. It won't be more than 8 or 9 inches away. Look at the new sensor to determine the length. Once you've located the plug, use the small straight edged screwdriver to press in the lock and at the same time, pull the sensor plug apart.

Spray a small amount of WD-40 on the threads of the sensor where screws into the exhaust system. Not too much because if it doesn't feel like it wants to loosen, you may have to heat it up with the hand torch a little bit and WD-40 is obviously flammable. The key here is not to damage the threads on the exhaust pipe. If that occurs, you will not be able to rethread the new sensor in tightly. Try loosening the sensor using the 22 millimeter wrench or the oxygen sensor socket and a ratchet. Give it a good tug, but do not force it off. Usually, if its going to come off, a good tug will loosen it and you'll be able to unscrew it by hand almost immediately. If it does not, apply a little heat with the hand torch to the exhaust pipe around the circumference of the sensor. Do not heat the sensor and the pipe. That would swell both metallic components and you'd be defeating the purpose. You want to make the pipe swell and loosen the sensor. Just a little heat should be enough. Allow to cool once you've broken the sensor loose if you had to use the torch.

Remove the sensor and compare it to the new one. If the new sensor did not have a small amount of anti-seize compound on the threads, apply some now. Just a small amount and only on the threads. Do not get any on the sensor head. Screw into the sensor hole and tighten with the hand wrench. You want it tight, but as you've noticed, the sensor only have 4 to 5 threads, so you do not want to over-tighten and strip the threads or you're going to have to buy another sensor.

Plug the sensor in until you hear and feel it click. There's only one way it will fit into the plug. Remove the tools and lower the vehicle. The check engine light may take a few days and a few cycles to reset. It is recommended that you go back to the parts store and have them reset the check engine code for you and then run the Blazer under normal conditions for a few monitor cycles (may take up to 70 miles or so) to see if it comes back on. You can also try disconnected the battery, but this will erase other data stored in the computer.

Items you will need

  • Car ramps (recommended) or a floor jack and two jack stands Wheel chock 22 millimeter open end hand wrench or an oxygen sensor socket and a 3/8-inch drive ratchet WD-40 Hand torch (if necessary) Small straight edged screwdriver Creeper (optional) Anti-seize compound

 How to Replace the Oxygen Sensor on an HHR

Locate the O2 sensor you wish to replace, near the catalytic converter on the exhaust manifold. The sensor looks like a golden peg with wires coming out of it.

Disconnect the wires by hand from where they hook into the HHR's electrical system. Take care not to damage the electrical socket, as you will need to plug the new O2 sensor back into it. But don't worry about damaging the O2 sensor's wires; you won't be reusing them.

Use a wrench or ratchet and socket to loosen and unscrew the O2 sensor. Use extra force if you haven't changed out the O2 sensor for a long period of time. Safely discard the sensor.

Spray the threads of your new O2 sensor with WD-40 or a similar lubricant, and then do the same to the threads of the screw-in hole from where you removed the old O2 sensor. This will ensure that you can screw the sensor in smoothly and without having to force it--which could potentially damage the threads.

Use your wrench or ratchet and socket to screw the new O2 sensor into place, and tighten the sensor down securely. Connect the wires to the appropriate electrical socket.

Items you will need

  • Ratchet or 22 mm wrench

  • 22 mm deep-dish socket or oxygen sensor socket

  • Replacement O2 sensor

  • Lubricant

 How to Change the Oxygen Sensor in a 2005 Chevy Cobalt

Place the Cobalt in "Park" on a level surface. Allow the Chevy to sit for 10 minutes. This will allow components to cool enough to touch but still be warm, which is ideal for replacing the oxygen sensor.

Open the hood of the Cobalt and identify the oxygen sensor. Look for a white, rubber, plug-type sensor on the passenger side of the exhaust manifold; this is the oxygen sensor.

Use a socket wrench paired with an oxygen sensor socket to loosen the sensor. Turn the wrench counter-clockwise until the oxygen sensor is loose. Remove the sensor from the manifold by pulling it off. The sensor will come off without much force.

Insert the replacement oxygen sensor onto the manifold. Secure the sensor by pushing it into place until the sensor clicks. Close the hood of the Cobalt.

Items you will need

  • Socket wrench

  • Oxygen sensor socket

  • Replacement oxygen sensor

 How to Change the Oxygen Sensor on a Chevy Cavalier

Locate the oxygen sensor that needs replacing. If you're replacing the front one (upstream), you can access it in the engine compartment by lifting the hood. If you are replacing the rear sensor (downstream), you'll need to lift the Cavalier's front end with the floor jack and support it safely and securely onto the jack stands. The front sensor is located in the front lower center of the engine and screwed into the header pipe. The rear sensor is located in the exhaust pipe near the catalytic converter. Put on safety glasses if you crawl under the Cavalier.

Locate the wire harness to the oxygen sensor. Use the flathead screwdriver to press in on the clip lock of the plug on the oxygen sensor wire and separate it from the wire harness.

Spray a liberal amount of penetrating oil on the threads of the oxygen sensor and allow the oil to soak in.

Place the box end wrench or socket onto the oxygen sensor and turn it counterclockwise to unthread it from the exhaust pipe. Remove the sensor.

Thread the new sensor into the oxygen sensor porthole in the exhaust pipe and tighten using the wrench or socket and a ratchet. Do not overtighten. Make sure its snug, but it is easy to strip the threads on the oxygen sensor so be careful.

Plug the oxygen sensor wire back into the wire harness and secure the wire so it does not dangle.

Remove the tools and either lower the vehicle or close the hood.

Items you will need

  • 22 millimeter box end stubby wrench or oxygen sensor socket and a ratchet

  • Oxygen sensor replacement

  • Floor jack and 2 jack stands (only if replacing rear sensor)

  • Safety glasses

  • Penetrating oil

  • Flathead screwdriver

 How to Change an Oxygen Sensor on a Chevy Venture

Remove the Oxygen Sensor

Start the engine and let it idle for three minutes to bring it up to operating temperature. then turn off the engine. You can remove the oxygen sensor much easier with the exhaust system above 120 F (48 C).

Lift the front of your Chevy Venture using a floor jack and support it on 2 jack stands.

Put on your goggles and locate the sensor or sensors you want to replace. You will find one on the front exhaust pipe, between the exhaust manifold and the catalytic converter. It is called the upstream oxygen sensor. The downstream sensor is just after the catalytic converter, threaded on the back pipe.

Unplug the oxygen sensor electrical connector.

Remove the sensor using a box-end wrench or a ratchet and oxygen sensor socket.

Install the Oxygen Sensor

Apply a light coat of anti-seize compound to the threads of the new oxygen sensor. Keep the tip of the new sensor free of compound, dirt and other foreign particles that may interfere with the unit operation.

Start the sensor by hand on the exhaust pipe. Then tighten the sensor using the box-end wrench or ratchet and sensor socket.

Plug the oxygen sensor electrical connector.

Lower the vehicle.

Items you will need

  • Floor jack and 2 jack stands

  • Goggles

  • Box-end wrench or Ratchet and oxygen sensor socket

  • Anti-seize compound

 How to Replace the Oxygen Sensor on a Chevy

Remove the Oxygen Sensor

Warm up the engine for about four minutes to bring it to operating temperature. Then turn off the engine. This will avoid damage to the exhaust pipe threads if that sensor has seized to the pipe.

Find the oxygen sensor or sensors you need to replace. The upstream sensor is located near the exhaust manifold and the downstream sensor on the back exhaust pipe, close to the catalytic converter.

Disconnect the oxygen sensor electrical connector. Depending on your particular Chevy model, both sensors may be disconnected from the engine compartment.

Lift the front of your Chevy model to reach the sensor you need to change, if necessary. Use a floor jack and two jack stands to support it.

Remove the oxygen sensor using a box-end wrench or a ratchet and oxygen-sensor socket.

Install the Oxygen Sensor

Apply a light coat of anti-seize compound to the threads of the new sensor. Avoid touching the tip of the sensor with the compound, which may ruin the unit.

Start the new sensor by hand on the exhaust pipe. Then tighten the unit using the box-end wrench or ratchet and oxygen-sensor socket.

Connect the sensor electrical connector.

Lower the vehicle if you had to lift it.

Items you will need

  • Penetrating oil, if necessary

  • Floor jack

  • Two jack stands

  • Box-end wrench or ratchet and sensor socket

  • Anti-seize compound

 How to Replace the Oxygen Sensor in a Chevy Express

Put on the safety glasses and start the van up if the engine is cold.

Crawl under the van to locate the correct oxygen sensor or sensors to replace. While the engine is running, spray penetrating lubricant along the threads of the oxygen sensor. Keep spraying on and off and allow the engine to run for a couple minutes to warm up the exhaust system.

Crawl back out and shut the engine off and then return to the oxygen sensor with the remaining tools.

Disconnect the wire harness plug from the oxygen sensor.

Place the wire into the slot on the side of the oxygen sensor socket and then place the socket onto the oxygen sensor. Attach the ratchet to the socket and turn the sensor counterclockwise to unscrew it from the exhaust port.

Insert the new oxygen sensor into the exhaust port and then thread it in by hand as far as it will go.

Tighten the sensor with the socket and ratchet clockwise until it's snug. Do not over-tighten or you'll strip the threads of the new sensor out.

Reconnect the wire harness connection. Remove the tools and old sensor.

Items you will need

  • Oxygen sensor socket and ratchet

  • Penetrating lubricant spray

  • Replacement oxygen sensor

  • Safety glasses

 How to Replace the Oxygen Sensor on a 2000 Silverado

Drive your Silverado for about 20 minutes at highway speeds to bring the engine to operating temperature. This will make it much easier to remove the oxygen sensor without damage to the boss threads on the exhaust system where the sensor mounts.

Park your Silverado on level ground and set the transmission to "Neutral." Raise the front of the Silverado with a floor jack, support the Silverado on two safety stands placed under the frame rails, and apply the parking brakes. Block one rear wheels with a chock on either side.

Open the hood and locate the oxygen sensor you need to replace. You may follow the left or right headed pipe that connects to the exhaust manifold toward the rear of the vehicle. You could use a diagnostic scan tool to determine which oxygen sensor has failed, or you can just replace them both and save the trouble of changing the older one when it fails later. You will find a sensor right before the catalytic converter and another one after. The sensor is a small cylinder, about the size of a spark plug, with an electrical wire at the end.

Trace the electrical wire from the sensor to find the connector. Examine the connector and remove the small plastic pin that secures both halves of the connector. Put it in a pocket. Unplug the connector.

Position an oxygen sensor socket on the sensor, unfasten the sensor from the exhaust pipe with a ratchet, and remove the sensor.

Apply a coat of anti-seize compound to the threads of the new sensor, making sure not to touch the tip of the sensor with the compound. Thread the sensor finger tight. Position the sensor socket on the sensor and tighten the sensor to 30 foot-pounds (41 Newton meters) with a torque wrench.

Plug in the sensor electrical connector and secure both halves with the plastic pin.

Lower your Silverado and remove the two chocks.

Items you will need

  • Floor jack

  • 2 safety stands

  • 2 chocks

  • Oxygen sensor socket

  • Ratchet

  • Anti-seize compound

  • Torque wrench

 How to Replace the Oxygen Sensor on a 1993 Chevy Corsica

Idle the engine for about 20 minutes to warm it up. This will help you ease the threads off the exhaust manifold.

Open the hood and remove the exhaust manifold shield if your particular model comes equipped with it. Use a ratchet, ratchet extension and socket.

Disconnect the negative (black) battery cable from the battery with a wrench. Secure it so it can't slip back into contact with the battery post.

Locate the oxygen sensor. It's mounted on the exhaust manifold close to the exhaust pipe that connects to the manifold. The sensor is a small metal cylinder, about the size of a spark plug, with electrical wires attached to it.

Unplug the sensor electrical connector.

Unfasten the oxygen sensor from the exhaust manifold with a ratchet and oxygen-sensor socket. If necessary, use penetrating lubricant to help you loosen the sensor, says Jimmy Nylund in the Auto Media website.

Apply a thin coat of electrically conductive anti-seize compound to the new sensor's threads if your new sensor comes without this coating already applied.

Install the new sensor finger-tight and tighten the sensor to 30 foot-pounds (40 Nm) with a torque wrench and the oxygen-sensor socket.

Plug the sensor electrical connector.

Replace the exhaust manifold shield if your Corsica model is equipped with it. Use the ratchet, ratchet extension and socket.

Reconnect the negative (black) battery cable to the battery post with the wrench.

Items you will need

  • Ratchet

  • Ratchet extension

  • Socket

  • Wrench

  • Oxygen sensor socket

  • Penetrating lubricant

  • Electrically conductive anti-seize compound

  • Torque wrench