Parts needed:
-O2 Oxygen Sensor Socket (optional, but makes the job way easier)
-New Oxygen Sensor (Bosch or NTK recommended)
-Ratchet or breaker bar
-Extensions if your O2 socket doesn't have any
-Flat head screwdriver
-WD40 or Liquid Wrench (helpful for stuck sensors)
-Zip Ties
-Shop towel or piece of cardboard
Here's how to do it:
1. Park your car in a safe area and turn off engine. Put the car in park and engage parking brake.
2. Locate the oxygen sensor. The O2 sensor is located in the exhaust system, just before the catalytic converter. It is a small, cylindrical-shaped sensor with a wire harness attached to it. You will need to locate both sensors, as they are on the driver and passenger sides. It is helpful to jack the car up or use ramps to make access easier.
3. Disconnect the wire harness. Disconnect the wire harness from the oxygen sensor by squeezing the tabs on the connector and pulling it apart.
4. Remove the old oxygen sensor. Use the O2 oxygen sensor socket to unscrew the oxygen sensor from the exhaust manifold. Be careful not to drop the oxygen sensor.
5. If sensor is stuck you may need to apply some WD40 or liquid wrench to the threads to loosen it. Let it soak in and try again after a few minutes.
6. You can also carefully tap on the sensor with the flat head screwdriver at the base to try and break the seal.
7. Once you have removed the oxygen sensor, clean up the sealing surface of the exhaust pipe.
8. Install the new oxygen sensor. Hand tighten the new oxygen sensor until it is snug. Then, use the ratchet or breaker bar to tighten it until it is fully tightened. Do not overtighten.
9. Reconnect the wire harness. Reconnect the wire harness to the oxygen sensor by squeezing the tabs on the connector and plugging it in.
10. Start the engine and let it run for a few minutes. Check for any leaks around the oxygen sensor.
11. Use the zip tie to secure the wires to any existing exhaust brackets or parts.
12. Test drive your car to make sure the oxygen sensor is working properly.
Note: If the oxygen sensor is not fully tightened, it may leak exhaust gas and cause the engine to run rich. If the oxygen sensor is overtightened, it may damage the threads on the exhaust manifold.
The above instructions are for replacing the downstream O2 sensor. Replacing the upstream O2 sensor is the same process, it is located on the catalytic converter itself and may be harder to reach.
