For 1990-2009 cars

#### Tools Required

J 39194 Oxygen Sensor Wrench

### Removal Procedure

Notice: The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Notice: The use of excessive force may damage the threads in the exhaust manifold/pipe.

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

Important: The in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the heated oxygen sensor (HO2S).

Important: The HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F).

1. Open the hood.
2. Remove the connector position assurance (CPA) retainer.
3. Disconnect the HO2S electrical connector (4) from the engine wiring harness electrical connector (2).
4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
5. Using the J 39194 , remove the position 2 HO2S.

### 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. Using the J 39194 , install the position 2 HO2S.

Tighten
Tighten the sensor to 42 N·m (31 lb ft).

3. Lower the vehicle.
4. Connect the HO2S electrical connector (4) to the engine wiring harness electrical connector (2).
5. Install the CPA retainer.
6. Close the hood.