GM Service Manual Online
For 1990-2009 cars only

Exhaust Seal Replacement 3.4L

Removal Procedure

  1. Raise and 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.


    Object Number: 372621  Size: SH

    Important: Use caution handling the pipe that contains an oxygen sensor. Do not cut the wire. For removal or repositioning disconnect the HO2S electrical connector.

  3. Remove the exhaust manifold pipe stud nuts from the exhaust manifold studs.

  4. Object Number: 289493  Size: SH

    Important: Support the exhaust system where hangers are removed.

  5. Remove the catalytic converter exhaust hangers.
  6. Reposition the exhaust system.

  7. Object Number: 107855  Size: SH
  8. Remove the exhaust manifold pipe gasket.

Installation Procedure


    Object Number: 107855  Size: SH
  1. Install the exhaust manifold pipe gasket.
  2. Install the exhaust system to the original position.

  3. Object Number: 289493  Size: SH
  4. Install the catalytic converter exhaust hangers.

  5. Object Number: 372621  Size: SH
  6. Remove the support from the exhaust system.
  7. 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 nuts to the exhaust manifold pipe studs.
  9. Tighten
    Tighten the nuts to 35 N·m (26 lb ft).

  10. Inspect the exhaust system for leaks and underbody contact.
  11. Lower the vehicle.

Exhaust Seal Replacement 3.8L

Removal Procedure

  1. Raise and 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.


    Object Number: 372626  Size: SH

    Important: Use caution handling the pipe that contains an oxygen sensor. Do not cut the wire. For removal or repositioning disconnect the HO2S electrical connector.

  3. Remove the exhaust manifold nuts from the exhaust manifold pipe studs.

  4. Object Number: 289493  Size: SH

    Important: Support the exhaust system where hangers are removed.

  5. Remove the catalytic converter exhaust hangers.
  6. Reposition the exhaust system.
  7. Remove the exhaust manifold pipe gasket.

Installation Procedure


    Object Number: 372626  Size: SH
  1. Install the exhaust manifold pipe gasket.
  2. Install the exhaust system to the original position.

  3. Object Number: 289493  Size: SH
  4. Install the catalytic converter exhaust hangers.
  5. Remove the support from the exhaust system.
  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 exhaust manifold pipe nuts to the exhaust manifold pipe studs.
  8. Tighten
    Tighten the nuts to 35 N·m (26 lb ft).

  9. Inspect the exhaust system for leaks and underbody contact.
  10. Lower the vehicle.