GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement 3.8L Engine

Removal Procedure

Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.


    Object Number: 222949  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the exhaust manifold bolts.
  3. Remove the exhaust pipe gaskets.

  4. Object Number: 222946  Size: SH
  5. Remove the connector position assurance (CPA) lock.
  6. Disconnect the oxygen sensor electrical connector.

  7. Object Number: 222948  Size: SH
  8. Remove the oxygen sensor.
  9. Loosen the exhaust pipe clamp bolt at the catalytic converter.

  10. Object Number: 21664  Size: SH
  11. Remove the catalytic converter hanger bolts.
  12. Remove the catalytic converter hanger from the hanger bracket.

  13. Object Number: 21662  Size: SH
  14. Twist and slide out the catalytic converter from the exhaust muffler.

Installation Procedure

Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.


    Object Number: 21662  Size: SH
  1. Twist and slide the catalytic converter into the exhaust muffler.

  2. Object Number: 21664  Size: SH
  3. Install the catalytic converter hanger to the hanger bracket.
  4. 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.

  5. Install the catalytic converter hanger bolts.
  6. Tighten
    Tighten the catalytic converter hanger bolts to 41 N·m (30 lb ft).


    Object Number: 222949  Size: SH
  7. Install the exhaust manifold bolts.
  8. Tighten
    Tighten the exhaust manifold bolts to 48 N·m (35 lb ft) alternating back and forth from the left to the right manifolds.

  9. Tighten the exhaust pipe clamp bolt at the catalytic converter.
  10. Tighten
    Tighten the exhaust pipe clamp bolt to 48 N·m (35 lb ft).


    Object Number: 222948  Size: SH
  11. Install the oxygen sensor.
  12. Tighten
    Tighten the oxygen sensor to 42 N·m (31 lb ft).


    Object Number: 222946  Size: SH
  13. Connect the oxygen sensor electrical connector.
  14. Install the CPA lock.
  15. Lower the vehicle.