For 1990-2009 cars

### Removal Procedure

1. Turn the ignition OFF.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
3. Disconnect the heated oxygen sensor (HO2S) electrical connector (bank 1 shown, bank 2 similar).
4. Remove the HO2S wiring harness from the transmission case.

Notice: Refer to Oxygen Sensor Notice in the Preface section.

Important: Removal of the oxygen sensor is easier when the engine temperature is above 48°C (120°F).

5. Remove the HO2S.

### Installation Procedure

Notice: Refer to Component Fastener Tightening Notice in the Preface section.

Important: New oxygen sensors should have a special anti-seize compound already applied to the sensor threads. If you are installing the original sensor, apply anti-seize compound GM P/N 5613695 or equivalent to the sensor threads.

1. Install the HO2S.

Tighten
Tighten the HO2S to 43 N·m (32 lb ft).

2. Connect the HO2S electrical connector (bank 1 shown, bank 2 similar).
3. Install the HO2S wiring harness to the transmission case.
4. Lower the vehicle.