GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39194 Oxygen Sensor Wrench

Notice: 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.

Removal Procedure

Notice: 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 in General Information.

  2. Object Number: 402074  Size: SH
  3. Remove the HO2S electrical connector retaining tab (1) from the HO2S electrical harness connector (2).
  4. Disconnect the HO2S electrical connector from the HO2S electrical harness connector (2).
  5. Important: Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

  6. Remove the oxygen sensor (4) from the exhaust pipe using the J 39194 .

Installation Procedure


    Object Number: 402074  Size: SH

    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.

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

  1. Install the oxygen sensor (4) to the exhaust pipe.
  2. Tighten
    Use the J 39194 to tighten the oxygen sensor to 41 N·m (30 lb ft).

  3. Connect the HO2S electrical connector to the HO2S electrical harness connector (2).
  4. Install the retaining tab (1) to the HO2S electrical connector.
  5. Lower the vehicle.