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

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Remove the connector position assurance (CPA) retainer (5).
3. Disconnect the HO2S electrical connector (7) from the engine wiring harness electrical connector (6).

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




4. Remove the HO2S (3).

Important: A special anti-seize compound is used on 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 be 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: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

2. Install the HO2S (3).

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




3. Connect the HO2S electrical connector (7) to the engine wiring harness electrical connector (6).
4. Install the CPA retainer (5).
5. Lower the vehicle.