GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2005 🢒 H2 🢒 Engine 🢒 Engine Exhaust 🢒 Exhaust Manifold Pipe Replacement

Removal Procedure
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the engine protection shield. Refer to Engine Protection Shield Replacement .

    3. Object Number: 664781 Size: SH
  3. Remove the exhaust muffler. Refer to Muffler Replacement .
  4. Remove the clip around the engine harness and the oxygen sensor pigtail.
  5. Disconnect the connector position assurance (CPA) retainer.
  6. Disconnect the oxygen sensor electrical connector.
  7. If replacing the exhaust manifold pipe, remove the oxygen sensor.

    8. Object Number: 664826 Size: SH
  8. Remove the exhaust manifold pipe nuts.

    9. Object Number: 863015 Size: SH
  9. Remove the exhaust manifold pipe.
  10. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.
  11. Discard the exhaust manifold pipe seal.

Installation Procedure

    Object Number: 863015 Size: SH
  1. Install a new exhaust manifold pipe seal to the exhaust manifold pipe.
  2. Install the exhaust manifold pipe.
  3. Apply lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
  4. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.

    5. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 664826 Size: SH
  5. Install the exhaust manifold pipe nuts.

    6. Tighten
    Tighten the nuts to 50 N·m (39 lb ft).


    Object Number: 664781 Size: SH
  6. If the exhaust manifold pipe was replaced perform the following:
    7. 6.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensor.
    6.2. Install the old oxygen sensor.

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

  7. If the exhaust manifold pipe was not replaced perform the following:
    8. 7.1. Connect the oxygen sensor electrical connector.
    7.2. Connect the CPA retainer.
    7.3. Install the clip around the engine harness and the oxygen sensor pigtail.
  8. Install the exhaust muffler. Refer to Muffler Replacement .
  9. Install the engine protection shield. Refer to Engine Protection Shield Replacement .

    10. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  10. Lower the vehicle.