Heated Oxygen Sensor (HO2S) Replacement (Post-Catalyst)

HEATED OXYGEN SENSOR (HO2S) REPLACEMENT (POST-CATALYST)

TOOLS REQUIRED
J 39194-C Oxygen Sensor Wrench

REMOVAL PROCEDURE




1. Raise and support the vehicle. Refer to Vehicle Lifting.

NOTE: Refer to Heated Oxygen Sensor (HO2S) Resistance Learn Reset Notice in Service Precautions.

2. Note the routing of the heated oxygen sensor (HO2S) electrical harness (2).
3. Disconnect the HO2S electrical connector in the engine compartment (1).




4. Using the J 39194 carefully remove the HO2S.
5. Lower the HO2S electrical harness away from the underbody (1).

NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Service Precautions.

INSTALLATION PROCEDURE

IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away but the glass beads will remain, making the sensor easier to remove. New or service sensors already have the compound applied to the threads. If the sensor is removed and is to be reinstalled, the threads must be coated with an anti-seize compound before reinstallation.

1. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
2. Carefully install the HO2S to the pipe.
3. Using the J 39194, or equivalent, tighten the HO2S.

NOTE: Refer to Component Fastener Tightening Notice in Service Precautions.

Tighten the HO2S to 41 N.m (30 lb ft).




4. Install the HO2S electrical harness into position as noted before removal (2).

NOTE: Refer to Heated Oxygen Sensor (HO2S) Resistance Learn Reset Notice in Service Precautions.




5. Connect the HO2S electrical connector (1).
6. Lower the vehicle.