GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 742280  Size: SH
  1. Raise and suitably support the vehicle with safety stands. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the exhaust manifold pipe nuts, left side shown, right side similar.
  3. Remove the exhaust pipe seal.
  4. Allow the muffler to hang.
  5. Lower the vehicle.

  6. Object Number: 470704  Size: SH

    Important: Twist the spark plug boot one-half turn in order to release the boot. Pull on the spark plug boot only. Do not pull on the spark plug wire or the wire could be damaged.

  7. Remove the spark plug wires from the spark plugs and ignition coils.
  8. Remove the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 8.1L.

  9. Object Number: 470737  Size: SH
  10. Remove the exhaust gas recirculation (EGR) pipe bolts from the EGR adapter plate.
  11. Remove the EGR pipe nuts from the exhaust manifold.
  12. Remove the EGR pipe bracket nuts.
  13. Remove the EGR pipe and gaskets. Discard the gaskets.

  14. Object Number: 742245  Size: SH
  15. Remove the starter motor heat shield bolt and nut.
  16. Remove the starter motor heat shield.

  17. Object Number: 470708  Size: SH
  18. Remove the exhaust manifold heat shield nuts.
  19. Remove the exhaust manifold heat shield.

  20. Object Number: 470725  Size: SH
  21. Remove the exhaust manifold bolts and nuts.
  22. Remove the exhaust manifold and gasket. Discard the gasket.
  23. Clean and inspect the exhaust manifold. Refer to Exhaust Manifold Cleaning and Inspection in Engine Mechanical-8.1L Unit Repair.

Installation Procedure


    Object Number: 470725  Size: SH
  1. Install a NEW exhaust manifold gasket.
  2. Install the exhaust manifold.
  3. 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.

  4. Install the exhaust manifold bolt and nuts.
  5. Tighten

        • Tighten the exhaust manifold bolt to 35 N·m (26 lb ft).
        • Tighten the exhaust manifold nuts to 16 N·m (12 lb ft).

    Object Number: 470708  Size: SH
  6. Install the exhaust manifold heat shield.
  7. Install the exhaust manifold heat shield nuts.
  8. Tighten
    Tighten the exhaust manifold heat shield nuts to 25 N·m (12 lb ft).


    Object Number: 742245  Size: SH
  9. Install the starter motor heat shield.
  10. Install the starter motor heat shield bolt and nut.

  11. Object Number: 470737  Size: SH
  12. Install the EGR pipe and NEW gaskets.
  13. Install the EGR pipe nuts to the exhaust manifold.
  14. Tighten
    Tighten the EGR pipe nuts to 30 N·m (30 lb ft).

  15. Install the EGR pipe bolts to the EGR adapter plate.
  16. Tighten
    Tighten the EGR pipe bolts to 30  N·m (22 lb ft).

  17. Install the EGR pipe bracket bolt.
  18. Tighten
    Tighten the EGR pipe bracket bolt to 50 N·m (37 lb ft).

  19. Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 8.1L.

  20. Object Number: 470704  Size: SH

    Important: Fully install the spark plug wire by pushing on the exposed end of the spark plug boot. Do not push the spark plug wire on to the spark plug by using the metal heat shield.

  21. Install the spark plug wires to the spark plugs and ignition coils.

  22. Object Number: 742280  Size: SH
  23. Raise and suitably support the vehicle with safety stands.
  24. Raise the muffler pipe onto position.
  25. Install the exhaust pipe seal.
  26. Install the exhaust manifold pipe nuts, left side shown, right side similar.
  27. Tighten
    Tighten the exhaust manifold pipe nuts to 50 N·m (37 lb ft).

  28. Lower the vehicle.