The O2 sensor is located in different places on a vehicle's exhaust system, depending on the make and model of the car, but the procedure required to replace them is essentially the same. To replace an O2 sensor socket, unplug the electrical connection from the sensor, unscrew the sensor from the exhaust system, and install a new sensor.
- Locate the sensor
Oxygen sensors are usually located within the exhaust stream near the catalytic converter or on the exhaust pipe. The sensor looks much like a spark plug and has electrical wiring attached to it.
- Disconnect the wiring
Using a flathead screwdriver, depress the tabs connecting the sensor wiring to the vehicle wiring. Pull the tabs apart to disconnect the wiring.
- Remove the O2 sensor
Using a socket or open-ended wrench, unscrew the O2 sensor from the exhaust system by turning the sensor in a counter clockwise-direction.
- Install the new sensor
Screw the new O2 sensor into the exhaust housing. If the sensor has a clip-on connection, snap it into place.
- Reset the maintenance warning light
If the Check Engine maintenance light appeared on your dashboard before you installed the new O2 sensor, clear the code that activates the warning indicator to turn the maintenance light off.