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

1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.
2. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement.
3. Remove the connector position assurance (CPA) retainer (3) from the HO2S electrical connection.
4. Disconnect the engine wiring harness electrical connector (2) from the heated oxygen sensor (HO2S) electrical connector (3).
5. Remove the HO2S electrical connector clip from the engine wiring harness tab.



6. Remove the HO2S from the exhaust manifold.

Note: 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.

Caution: Refer to Fastener Caution in the Preface section.

2. Install the HO2S to the exhaust manifold and tighten the sensor to 42 N·m (31 lb ft).



3. Connect the engine wiring harness electrical connector (2) to the HO2S electrical connector (3).
4. Install the HO2S electrical connector clip to the engine wiring harness tab.
5. Install the CPA retainer (3) to the HO2S electrical connection.
6. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement.
7. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement.