Tools Required

J 39194-B Heated Oxygen Sensor Wrench

The heated oxygen sensor (HO2S) 2 may be difficult to remove when engine temperature is less than 48°C (120°F). Excessive force may damage the threads in the exhaust pipe.

1. Turn OFF the ignition.



2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Disconnect the HO2S 2.

Important : A special anti-seize compound is used on the HO2S 2 threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before reinstallation.

4. Using the J 39194-B , carefully back out the HO2S 2.

1. Coat the threads of the HO2S 2 with anti-seize compound GM P/N 25613695, or an equivalent, if necessary.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Using the J 39194-B install the HO2S 2.

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

3. Connect the H02S 2 sensor.
4. Lower the vehicle.