Removal Procedure
- Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle.
- Unscrew the heated oxygen sensor (HO2S) sensor from the catalytic converter.
- Remove the connector position assurance (CPA) retainer.
- Disconnect the HO2S electrical connector (3).
Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.
Caution: Refer to Excessive Force and Oxygen Sensor Caution in the Preface section.
Installation Procedure
- Connect the HO2S electrical connector (3).
- Install the CPA retainer.
- If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
- Install the HO2S (2). Tighten the sensor to 42 N·m (31 lb ft).
- Lower the vehicle.
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 Component Fastener Tightening Caution in the Preface section.
Note: If the HO2S sensor is connected to the main wiring harness during installation. Rotate the HO2S sensor several turns counterclockwise before threading the HO2S sensor into the catalytic converter. This action of initially reverse winding of the pigtail wires will prevent a condition where the HO2S sensor pigtail wires become severely twisted or binding once the HO2S sensor is installed into the catalytic converter.
