For 1990-2009 cars

### Tools Required

J 39194 Heated Oxygen Sensor Wrench

### Removal Procedure

1. Turn OFF the ignition.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Disconnect the sensor harness connector.

Notice: 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.

Important: Removal of the oxygen sensor is easier when the engine temperature is above 48°C (120°F).

Important: Replace the sensors only. Do not attempt to repair any sensors.

4. Remove the affected oxygen sensors using the J 39194 :

• | Bank 1 sensor 2 (1)

• | Bank 1 sensor 1 (2)

• | Bank 2 sensor 1 (3)

• | Bank 2 sensor 2 (4)

### Installation Procedure

Notice: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Important: A special anti-seize compound is used on the oxygen sensor threads. The new service sensors should have the compound already applied to the threads. Coat the threads of a reused sensor with anti-seize compound GM P/N 5613695 or the equivalent.

1. Install the new oxygen sensors.

Tighten
Tighten the heated oxygen sensors to 30 N·m (22 lb ft):

• | Bank 1 Sensor 2 (1)

• | Bank 1 Sensor 1 (2)

• | Bank 2 Sensor 1 (3)

• | Bank 2 Sensor 2 (4)

Important: The harness must not contact any of the hot exhaust components. The rear heated oxygen sensor (HO2S) pigtail has white tape at the intervals, indicating the proper location of each retaining clip. When connecting the sensor pigtail to the harness, ensure that the connector seal is crushed uniformly all the way around between the connectors.

2. Connect the sensor harness connector.
3. Lower the vehicle.