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

1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
2. Remove the engine wiring harness heated oxygen sensor (HO2S) electrical connector clip from the engine harness.
3. Remove the connector position assurance (CPA) retainer (5) from the HO2S electrical connection.
4. Disconnect the engine wiring harness electrical connector (2) from the HO2S electrical connector (1).
5. Raise and support the vehicle to an appropriate height to reach the HO2S. Refer to Lifting and Jacking the Vehicle .



6. Remove the HO2S from the exhaust manifold.

Important: A special anti-seize compound is used in the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to reinstalled, the threads must have anti-seize compound applied before the reinstallation.

1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.

Notice: Refer to Fastener Notice in the Preface section.

2. Install the HO2S to the exhaust manifold.

Tighten
Tighten the sensor to 42 N·m (31 lb ft).

3. Lower the vehicle.



4. Connect the engine wiring harness electrical connector (2) to the HO2S electrical connector (1).
5. Install the engine wiring harness HO2S electrical connector clip to the engine harness.
6. Install the CPA retainer (5) to the HO2S electrical connection.
7. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .