GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39194-B Heated Oxygen Sensor Wrench

Removal Procedure

Notice: Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

Notice: Take care when handling oxygen sensors. The electrical connector and louvered end must be kept free of contaminants. Do not use cleaning solvents on the sensor. Do not drop or mishandle the sensor.

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 GM P/N 12377953 or equivalent.


    Object Number: 296092  Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Disconnect the heated oxygen sensor (HO2S) electrical connector.
  3. Remove the HO2S from the exhaust pipe using the J 39194-B  (1).

Installation Procedure


    Object Number: 296092  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: Ensure that the correct replacement HO2S is used. The engine HO2S 1 and the post-converter HO2S 2 are both 6.6-watt Denso sensors. Due to differences in pigtail length, the sensors use different connectors and are not interchangeable.

  1. Install the HO2S (1) to the rear exhaust pipe.
  2. Tighten
    Use the J 39194-B to tighten the HO2S to 41 N·m (30 lb ft).

  3. Connect the HO2S electrical connector.
  4. Lower the vehicle.