GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement 3.4L

Removal Procedure

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.


    Object Number: 372621  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Disconnect the heated oxygen sensor electrical connector.
  3. Remove the exhaust manifold pipe stud nuts.

  4. Object Number: 372616  Size: SH
  5. Remove the catalytic converter bolts.
  6. Remove the three way catalytic converter.

  7. Object Number: 372612  Size: SH
  8. Remove the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.4L.

Installation Procedure


    Object Number: 372612  Size: SH
  1. Install the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.4L.

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


    Object Number: 372616  Size: SH
  5. Install and support the three way catalytic converter.
  6. Install the catalytic converter bolts.

  7. Object Number: 372621  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.

  8. Install the exhaust manifold pipe stud nuts.
  9. Tighten

        • Tighten the exhaust manifold pipe stud nuts to 32 N·m (24 lb ft).
        • Tighten the catalytic converter bolts to 45 N·m (33 lb ft).

    Object Number: 372612  Size: SH
  10. Connect the heated oxygen sensor electrical connector.
  11. Inspect for leaks and underbody contact.
  12. Lower the vehicle.

Catalytic Converter Replacement 3.8L

Removal Procedure

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 assembly. Never reinstall the original gasket.


    Object Number: 372626  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Disconnect the heated oxygen sensor electrical connector.
  3. Remove the exhaust manifold pipe stud nuts.

  4. Object Number: 372616  Size: SH
  5. Remove the catalytic converter bolts.
  6. Remove the three way catalytic converter.
  7. Remove the exhaust manifold pipe gasket at the catalytic converter front flange.

  8. Object Number: 372612  Size: SH
  9. Remove the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.8L.

Installation Procedure


    Object Number: 372612  Size: SH
  1. Install the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls - 3.8L.
  2. Install a new exhaust manifold pipe gasket to the exhaust manifold pipe studs.
  3. Notice: Refer to Catalytic Converter Movement Notice in the Preface section.


    Object Number: 372616  Size: SH
  4. Install and support the three way catalytic converter.
  5. Install the catalytic converter bolts.

  6. Object Number: 372626  Size: SH
  7. Install the exhaust manifold pipe stud nuts.
  8. 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.

    Tighten

        • Tighten the exhaust manifold pipe stud nuts to 32 N·m (24 lb ft).
        • Tighten the catalytic converter bolts to 45 N·m (33 lb ft).
  9. Connect the heated oxygen sensor electrical connector.
  10. Inspect for leaks and underbody contact.
  11. Lower the vehicle.