Caution: Handle the oxygen sensors carefully in order to prevent damage to the component. Keep the electrical connector and the exhaust inlet end free of contaminants. Do not use cleaning solvents on the sensor. Do not drop or mishandle the sensor.

Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution in the Preface section.

Note: Remove the heated oxygen sensors (HO2S) with the engine temperature above 48°C (120°F). Otherwise the HO2S may be difficult to remove.

1. Remove the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement.
2. Disconnect the engine harness electrical connector from the heated oxygen sensor (HO2S).



3. Remove the HO2S.

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 components and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation

1. If reusing the old HO2S, 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.

Tighten
Tighten the sensor to 41 N·m (30 lb ft).




3. Connect the engine harness electrical connector to the HO2S.
4. Install the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement.