GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 39194 Oxygen Sensor Wrench

Removal Procedure


    Object Number: 911099  Size: SH

    Caution: The Heated Oxygen Sensor (HO2S) and the Oxygen Sensor use a permanently attached pigtail and connector. Do not remove this pigtail from the Heated Oxygen Sensor. Damage or the removal of the pigtail or the connector could affect the proper operation of the sensor.

    Take care when handling the HO2S and the O2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Also avoid using cleaning solvents of any type. Do not drop the HO2S or the O2S. Do not roughly handle the HO2S or the O2S.

    Caution: The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Remove the heated oxygen sensor (HO2S) electrical connector retaining clip from the HO2S electrical harness connector.
  3. Disconnect the HO2S electrical connector from the HO2S electrical harness connector.
  4. Note: Remove the oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

  5. Use the J 39194 to remove the O2S from the exhaust pipe.

Installation Procedure

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

    Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 911099  Size: SH

    Note: A special anti-seize compound is used on the O2S threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound GM P/N 12377953 or equivalent.

  1. Install the O2S to the exhaust pipe.
  2. Tighten
    Use the J 39194 to tighten the O2S to 42 N·m (31 lb ft).

  3. Connect the HO2S electrical connector to the HO2S electrical harness connector.
  4. Install the HO2S electrical connector retaining clip to the HO2S electrical harness connector.
  5. Lower the vehicle.