GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39194-B Heated Oxygen Sensor Wrench

Removal Procedure

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  2. Object Number: 762509  Size: SH
  3. Disconnect the pre (1) and post (4) heated oxygen (HO2S) sensor electrical connectors.

  4. Object Number: 762508  Size: SH
  5. Remove the muffler pipe flange bolts (1).

  6. Object Number: 231136  Size: SH
  7. Remove the exhaust manifold flange nuts.

  8. Object Number: 159595  Size: SH
  9. Remove the catalytic converter support bracket bolt(s) (1).
  10. Remove the catalytic converter(s) from the vehicle.

  11. Object Number: 231136  Size: SH
  12. Remove the exhaust manifold flange gasket.
  13. Use J 39194-B to remove the heated oxygen sensors.

Installation Procedure

    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.

  1. Use J 39194-B to install the heated oxygen sensors.
  2. Tighten
    Tighten the heated oxygen sensor to 42 N·m (31 lb ft).


    Object Number: 231136  Size: SH
  3. Install the exhaust manifold flange gasket.
  4. Install the catalytic converter(s) to the vehicle.

  5. Object Number: 159595  Size: SH
  6. Install the catalytic converter support bracket bolt(s) (1).
  7. Tighten
    Tighten the catalytic converter support bracket bolt(s) (1) to 20 N·m (15 lb ft).


    Object Number: 231136  Size: SH
  8. Install the exhaust manifold flange nuts.
  9. Tighten
    Tighten the exhaust manifold flange nuts to 25 N·m (18 lb ft).


    Object Number: 762508  Size: SH
  10. Install the muffler pipe flange bolts (1).
  11. Tighten
    Tighten the muffler pipe flange bolts (1) to 40 N·m (30 lb ft).


    Object Number: 762509  Size: SH
  12. Connect the pre (1) and post (4) heated oxygen (HO2S) sensor electrical connectors.
  13. Inspect the exhaust system clearances.
  14. Lower the vehicle.
  15. Inspect the exhaust system for leaks.