GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Disconnect the heated oxygen sensor (HO2S) wiring harness connector and retainers.
  3. Notice: Refer to Catalytic Converter Movement Notice in the Preface section.

  4. Suitably support the exhaust system.

  5. Object Number: 372616  Size: SH
  6. Remove the catalytic converter bolts.
  7. Remove the catalytic converter gasket.

  8. Object Number: 407377  Size: SH
  9. Remove the engine right exhaust manifold pipe stud nuts from the exhaust manifold pipe studs.
  10. Remove the three-way catalytic converter pipe.
  11. Remove the exhaust manifold pipe gasket.

  12. Object Number: 372612  Size: SH
  13. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor (HO2S) Replacemen in Engine Controls - 3.5L.

Installation Procedure


    Object Number: 372612  Size: SH
  1. Install the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor (HO2S) Replacement in Engine Controls - 3.5L.

  2. Object Number: 407377  Size: SH
  3. Install the exhaust manifold gasket.
  4. Notice: Refer to Catalytic Converter Movement Notice in the Preface section.

  5. Install the three-way catalytic converter.
  6. 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.

  7. Install the engine right exhaust manifold pipe stud nuts to the exhaust manifold pipe studs.
  8. Tighten
    Tighten the engine right exhaust manifold pipe stud nuts to 32 N·m (24 lb ft).


    Object Number: 372616  Size: SH
  9. Install the catalytic converter gasket.
  10. Install the catalytic converter bolts.
  11. Tighten
    Tighten the catalytic converter bolts to 45 N·m (33 lb ft).

  12. Remove the support from the exhaust system.
  13. Connect the heated oxygen sensor (HO2S) wiring harness connector and retainers.
  14. Inspect for leaks and underbody contact.
  15. Lower the vehicle.