For 1990-2009 cars

### Removal Procedure

1. Turn the ignition OFF.
2. Remove the fuel injector sight shield, if necessary. Refer to Fuel Injector Sight Shield Replacement.
3. Disconnect the heated oxygen sensor (HO2S) electrical connector.
4. Remove the HO2S electrical connector from the wiring harness bracket.
5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.

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

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

6. Remove the heated oxygen sensor from the catalytic converter.

### Installation Procedure

Caution: Refer to Fastener Caution 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 to the catalytic converter and tighten to 43 N·m (32 lb ft).
2. Lower the vehicle.
3. Install the HO2S electrical connector to the wiring harness bracket.
4. Connect the HO2S electrical connector.
5. Install the fuel injector sight shield, if necessary. Refer to Fuel Injector Sight Shield Replacement.