How do you replace an O2 sensor?

To replace an oxygen sensor, loosen the sensor with a specially designed wrench, and enlist the help of a breaker bar to remove the sensor entirely. You need a high-quality penetrant spray, an oxygen sensor wrench, a breaker bar and a screw-type oxygen sensor.

1. Consult your repair manual

   Consult the repair manual for the vehicle to determine whether you have a screw-in or welded-in type of oxygen sensor. Do not attempt to replace the sensor yourself if it has a welded-in style.

2. Apply the penetrant

   Spray the penetrant over the oxygen sensor where it comes loose.

3. Slide on the wrench

   Slide the specialized wrench over the sensor.

4. Loosen the sensor

   Insert the end of a breaker bar into the notch on the wrench. Twist the bar until the sensor loosens, and then disconnect the wires to remove it.

5. Install the new sensor

   Install the new sensor in the same way as the old, and use your hand to tighten it most of the way.

6. Secure the sensor

   Use the wrench to secure the sensor the rest of the way, and then connect the wires to the new sensor.

7. Reset the engine light

   If a faulty oxygen sensor caused the Check Engine light to illuminate, reset the light.