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

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
2. Unbolt the front propeller shaft from the front differential, if equipped with four wheel drive (4WD). Refer to Front Propeller Shaft Replacement.
3. Remove the connector position assurance (CPA) retainer (4).
4. Disconnect the engine wiring harness electrical connector (7) from the HO2S.
5. Remove the HO2S electrical connector clip (6) from the fuel line clip.

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




6. Remove the HO2S (1).

Note: 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.

Caution: Refer to Fastener Caution in the Preface section.




1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
2. Install the HO2S (1).

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




3. Connect the engine wiring harness electrical connector (7) to the HO2S.
4. Install the engine wiring harness electrical connector clip (6) to the fuel line clip.
5. Install the CPA retainer (4).
6. Install the front propeller shaft to the front differential, if equipped with 4WD. Refer to Front Propeller Shaft Replacement.
7. Lower the vehicle.