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

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

TOOLS REQUIRED
J 39194-C Oxygen Sensor Wrench

REMOVAL PROCEDURE

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




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

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

5. Lower the HO2S electrical harness away from the underbody (1).

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.

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

3. Using the J 39194, or equivalent, tighten the HO2S.

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

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




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




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