GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Pipe Replacement 6.0L, 6.6L, and 8.1L Engines

Removal Procedure


    Object Number: 665520  Size: SH
  1. Depending on which side is being replaced, perform one of the following steps:
  2. • Remove the exhaust muffler nuts.
    • or
    • Loosen the exhaust pipe clamp.
  3. Remove the necessary exhaust system hangers so that the pipes can be separated.
  4. Use a jack stand to support the exhaust.

  5. Object Number: 664781  Size: SH
  6. If equipped with a 6.0L or 8.1L engine, perform the following:
  7. 4.1. Remove the clip around the engine harness and the oxygen sensor pigtail.
    4.2. Disconnect the connector position assurance (CPA) retainer.
    4.3. Disconnect the oxygen sensor electrical connector.
    4.4. If replacing the exhaust manifold pipe, remove the oxygen sensor.

    Object Number: 664826  Size: SH
  8. if equipped with a 6.0L or 8.1L engine, remove the exhaust manifold pipe nuts.

  9. Object Number: 694338  Size: SH
  10. If equipped with a 6.6L engine, remove the exhaust muffler nuts.

  11. Object Number: 668379  Size: SH
  12. If equipped with a 6.6L engine, loosen the exhaust pipe clamp.
  13. Slide the exhaust pipe clamp up onto the exhaust pipe adapter.

  14. Object Number: 344263  Size: SH
  15. If equipped with a 6.0L or 8.1L engine, remove the exhaust manifold pipe.
  16. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.
  17. Discard the exhaust manifold pipe seal.

  18. Object Number: 694896  Size: SH
  19. If equipped with a 6.6L engine, remove the exhaust manifold pipe.
  20. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.

Installation Procedure


    Object Number: 694896  Size: SH
  1. If equipped with a 6.6L engine, install the exhaust manifold pipe.
  2. Apply water based lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
  3. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.

  4. Object Number: 344263  Size: SH
  5. If equipped with a 6.0L or 8.1L engine, install a new exhaust manifold pipe seal to the exhaust manifold pipe.
  6. Install the exhaust manifold pipe.
  7. Apply lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
  8. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.

  9. Object Number: 694338  Size: SH
  10. If equipped with the 6.6L engine, install the exhaust muffler nuts until snug.
  11. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 668379  Size: SH

    Important: Ensure that the manifold pipe is square to the exhaust pipe adapter.

  12. If equipped with a 6.6L engine, slide the exhaust pipe clamp down and around the pipe connection.
  13. Tighten the exhaust pipe clamp and muffler nuts.
  14. Tighten

        • Tighten the clamp to 40 N·m (30 lb ft).
        • Tighten the nuts to 40 N·m (30 lb ft).

    Object Number: 664826  Size: SH
  15. If equipped with a 6.0L or 8.1 L engine, install the exhaust manifold pipe nuts.
  16. Tighten
    Tighten the nuts to 50 N·m (39 lb ft).


    Object Number: 664781  Size: SH
  17. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was replaced perform the following:
  18. 12.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensor.
    12.2. Install the old oxygen sensor.

    Tighten
    Tighten the oxygen sensor to 42 N·m (31 lb ft).

  19. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was not replaced perform the following:
  20. 13.1. Connect the oxygen sensor electrical connector.
    13.2. Connect the CPA retainer.
    13.3. Install the clip around the engine harness and the oxygen sensor pigtail.
  21. Install the exhaust pipe/catalytic converter to the vehicle.
  22. Install the exhaust system hangers.

  23. Object Number: 665520  Size: SH
  24. Depending on which side is being replaced, perform one of the following steps:
  25. • Install the exhaust muffler nuts.

    Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

    • or
    • Install a NEW exhaust pipe clamp.

    Tighten
    Tighten the clamp to 44 N·m (33 lb ft).