GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Important: The three-way catalytic converter is serviced by replacing the entire assembly. Always replace the gasket at the front flange when servicing the three-way catalytic converter. Never reinstall the original gasket.

  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Notice: Refer to Catalytic Converter Movement Notice in the Preface section.

  3. Suitably support the exhaust system.

  4. Object Number: 368878  Size: SH
  5. Remove the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.1L.

  6. Object Number: 368881  Size: SH
  7. Remove the three-way catalytic converter bolts.

  8. Object Number: 368883  Size: SH
  9. Remove the exhaust manifold pipe stud nuts.
  10. Remove the three-way catalytic converter.

  11. Object Number: 107855  Size: SH
  12. Remove the exhaust manifold pipe gasket.

Installation Procedure


    Object Number: 107855  Size: SH
  1. Install a new exhaust manifold pipe gasket.
  2. Notice: Refer to Catalytic Converter Movement Notice in the Preface section.


    Object Number: 368883  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.

  3. Install and support the three-way catalytic converter.
  4. Install the exhaust manifold pipe stud nuts.
  5. Tighten
    Tighten the exhaust manifold pipe stud nuts to 32 N·m (24 lb ft).


    Object Number: 368881  Size: SH
  6. Install the three-way catalytic converter bolts.
  7. Tighten
    Tighten the three-way catalytic converter bolts to 45 N·m (33 lb ft).


    Object Number: 368878  Size: SH
  8. Install the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.1L.
  9. Inspect the exhaust system for leaks and underbody contact.
  10. Lower the vehicle.