GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 78428  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. 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.

  3. Remove the catalytic converter pipe to exhaust manifold flange nuts.
  4. Remove the catalytic converter pipe from the exhaust manifold.
  5. Remove and discard the seal.
  6. Inspect the exhaust manifold studs for damage.
  7. Remove any damaged studs.

Installation Procedure


    Object Number: 78428  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.

  1. Install any studs that were removed.
  2. Tighten
    Tighten the exhaust manifold studs to 18 N·m (13 lb ft).

  3. Install the catalytic converter pipe and NEW seal to the exhaust manifold.
  4. Install the catalytic converter pipe to exhaust manifold flange nuts.
  5. Tighten
    Tighten the catalytic converter pipe to manifold flange bolts to 65 N·m (48 lb ft).

  6. Lower the vehicle.
  7. 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.

  8. Inspect for any exhaust leaks and proper alignment of the exhaust system.