How to Change an Oxygen Sensor on Honda Cars

A Honda car has two sensors that read oxygen levels in the exhaust when the engine is running. The oxygen level data is used by a Honda car computer to control fuel supply and ignition. Located before and after the catalytic converters, the sensors can go bad and cause the engine to run poorly. A bad oxygen sensor can result in an engine light that tells you something needs to be fixed--a poor-running engine that blows smoke out the tailpipe, fails an emissions test or doesn't run at all. Change an oxygen sensor on a Honda car using an oxygen sensor socket and some penetrating oil.

Under The Hood:

• How to Change an Oxygen Sensor on a Honda Civic
• How to Replace the Oxygen Sensor on a Honda CRV
• How to Replace an Oxygen Sensor on a 1996 Honda Accord
• How to Replace the Oxygen Sensor in a 1991 Honda Accord
• How to Replace an Oxygen Sensor on a 1998 Accord

 How to Change an Oxygen Sensor on a Honda Civic

Apply penetrating oil around the base of the bad oxygen sensor where it threads into the exhaust pipe or exhaust manifold. The Honda Civic has two sensors that monitor exhaust gases produced by the engine during operation. One sensor is located before the catalytic converter and one is after. The one before can be found sticking out of the exhaust manifold and the other out of the exhaust by the mufflers. Depending on which sensor is bad, you will be working either inside the engine compartment or underneath the vehicle.

Disconnect an oxygen sensor from the wiring harness at the wiring adapter that holds it in place. The wiring adapter has a tab that locks two connectors together, and it needs to be unlatched to separate the sensor connector from the harness connector. Lift the locking tab and pull the adapters apart. The sensor and its wire can be removed without twisting any harness wires as the sensor is turned inside the threaded collar when removed.

Place an oxygen sensor socket over the top of the sensor. These sockets have a space for the sensor wire to pass through the side of the socket, allowing the socket to be placed around the sensor and the sensor to be loosened from its position in the sensor-mounting collar. Turn the socket counterclockwise to loosen the sensor within its threaded mounting collar.

Disconnect the socket from around the sensor when it has become loose enough to remove by hand, or continue to turn the socket and the sensor counterclockwise until it is free from the threaded collar holding it in place.

Remove the sensor and discard properly. Oxygen sensors use precious metals to read the oxygen levels in exhaust gases. These sensors should be recycled properly.

Insert a new oxygen sensor into the threaded sensor collar by hand until it is tight. Place the sensor socket over the top of the new sensor, and use the ratcheting wrench to continue tightening. When the sensor has been tightened securely, connect the new sensor to the old wiring harness using the new sensor's wiring adapter.

 How to Replace the Oxygen Sensor on a Honda CRV

Confirm that your oxygen sensor has to be replaced by taking your Honda CRV to an auto parts store that has a code machine. Technicians can hook up your CRV to their machine to get a code to confirm that your oxygen sensor is faulty. There usually is no fee for this service.

Purchase your oxygen sensor. The model number will depend on the year of your CRV. An auto parts store can assist you in obtaining the correct part.

Acquire an oxygen sensor wrench. You can rent one from a tools rental store or an auto parts store, if you don't have one or don't want to purchase one.

Drive your car onto auto ramps and set the parking brake, or jack it up so that you can get underneath the car to work.

Locate the two oxygen sensors. One is at the front and one at the back of the catalytic converter. The code that you had detected earlier indicates the faulty sensor. Or you could replace both.

Disconnect your negative battery cable.

Unscrew the bracket holding the sensors in place. This will allow access to the sensors.

Remove the sensor by using the oxygen sensor wrench. If the sensor is difficult to remove, you can warm up the engine by running it for a few minutes or you can spray the sensor with a lubricant.

Put the new sensor in place and tighten the bracket holding the sensors.

Reattach the negative battery cable.

Drive your car five to 10 miles after completing the job. This will cause the Honda's "Check Engine" light to reset.

 How to Replace an Oxygen Sensor on a 1996 Honda Accord

Drive your Honda for about 20 minutes to raise the temperature in the engine and exhaust system. This will prevent you from using too much force to unfasten the sensor and possibly causing damage to the exhaust pipe.

Park your Accord, turn off the key and disconnect the ground (black) battery cable with a wrench.

Locate the upstream sensor at the headed pipe, which connects to the exhaust manifold, and the second, down stream sensor, after the catalytic converter.

Raise the front of your Accord with a floor jack and position a safety stand on each side for support, if you need to replace the downstream sensor as well.

Unplug the sensor electrical connector and install an oxygen sensor socket over the sensor. Unfasten the sensor with a ratchet.

Coat the threads of the new sensor with anti-seize compound, if your new sensor is not coated already. This will help you easily replace the sensor next time.

Thread the new sensor in place finger tight, then tighten the sensor with the socket and ratchet.

Plug in the oxygen sensor electrical connector and lower your Accord with the floor jack, if you had to raise it.

Reconnect the ground (black) battery cable with the wrench.

 How to Replace the Oxygen Sensor in a 1991 Honda Accord

Place your Accord in park and let it cool. This will allow the engine and exhaust to cool and preventing burns during the oxygen sensor replacement.

Open the driver's side door and pull the hood latch to pop your hood. Open the hood and locate the oxygen sensor on the passenger side on the exhaust manifold. The oxygen sensor looks like a round plug.

Spray some WD-40 around the edges of the oxygen sensor to loosen it for easy removal. Use the wrench to unscrew the sensor and remove it from it's port. Unplug the sensor's wires from the electrical harness.

Apply some of the anti-seize paste to the threads of the new oxygen sensor. This will make for easier removal for the next time. Be careful not to get any of the paste on the sensor itself or it could cause it to malfunction or fail prematurely.

Connect the wires of the sensor into the electrical wiring harness of the Accord. Screw the sensor in place securely with the wrench. The new sensor will be working right away. Close the car hood.

 How to Replace an Oxygen Sensor on a 1998 Accord

Raise the front of your Accord with a jack, then position a set of jack stands under the front of the car. Lower the jack until the jack stands are supporting the weight of the car. Remove the jack from under the car.

Locate the oxygen sensors in the exhaust system. The first is in the head pipe, just in front of the mounting flange for the catalytic converter. The second is right behind the catalytic converter, and it is technically a catalytic monitor. The process is the same for replacing either one.

Locate the wiring harness connector where the pigtail from the oxygen sensor and the wiring harness from the car come together. Release the locking clip and separate the two halves of the connector.

Remove the oxygen sensor from the exhaust system using a oxygen sensor socket and ratchet. Turn the sensor counterclockwise until it is free of the exhaust pipe. Discard the old sensor.

Install a new oxygen sensor in place of the one you removed and tighten it to 33 pound-feet of torque with a torque wrench. Install the connector on the sensor's wiring pigtail into the connector on the car's wiring harness. Push the two connectors together until the locking tab engages.

Position the jack under the front of the Accord and lift the car off the jack stands. Remove the jack stands from under the car and lower the Accord.