GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2006 🢒 GMC Sierra Denali 🢒 Engine 🢒 Engine Exhaust 🢒 Exhaust Seal Replacement

Removal Procedure

    Object Number: 664828 Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
    3. 2.1. Remove the clip from around the engine harness and the oxygen sensor pigtail.
    2.2. Disconnect the connector position assurance (CPA) retainer.
    2.3. Disconnect the forward oxygen sensor electrical connector.

    Object Number: 664951 Size: SH
  3. If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
    4. 3.1. Unclip the oxygen sensor electrical connector from the hose clip.
    3.2. Disconnect the CPA retainer.
    3.3. Disconnect the oxygen sensor electrical connector (1).

    Object Number: 665040 Size: SH
  4. If equipped with a 6.0L or 8.1L engine, perform the following:
    5. 4.1. Disconnect the CPA retainer.
    4.2. Disconnect the oxygen sensor electrical connector (1).
  5. Support the catalytic converter or exhaust manifold pipe with adjustable jackstands.

    6. Object Number: 858550 Size: SH
  6. If equipped with a 4.3L, 4.8L, or 5.3L engine, remove the left exhaust manifold pipe nuts.

    7. Object Number: 858553 Size: SH
  7. If equipped with a 4.3L, 4.8L, or 5.3L engine, remove the right exhaust manifold pipe nuts.

    8. Object Number: 858574 Size: SH
  8. If equipped with a 6.0L or 8.1L engine, remove the right exhaust manifold pipe nuts.

    9. Object Number: 858568 Size: SH
  9. If equipped with a 6.0L or 8.1L engine, perform the following:
    10. 9.1. Remove the left exhaust manifold pipe nuts.
    9.2. Remove the exhaust hanger mounting bracket bolts.
  10. Lower the catalytic converter or exhaust manifold pipe using the adjustable jackstands.
  11. Remove the exhaust manifold pipe seal(s).

Installation Procedure

    Object Number: 858568 Size: SH
  1. Install the exhaust manifold pipe seal(s).
  2. Raise the catalytic converter or exhaust manifold pipe using the adjustable jackstands.

    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.

  3. If equipped with a 6.0L or 8.1L engine, perform the following:
    4. 3.1. Install the exhaust hanger mounting bracket bolts.
    3.2. Install the left exhaust manifold pipe nuts.

    Tighten

        • Tighten the bolts to 12 N·m (106 lb in).
        • Tighten the nuts to 50 N·m (39 lb ft).

    Object Number: 858574 Size: SH
  4. If equipped with a 6.0L or 8.1L engine, install the right exhaust manifold pipe nuts.

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


    Object Number: 858553 Size: SH
  5. If equipped with a 4.3L, 4.8L, or 5.3L engine, install the right exhaust manifold pipe nuts.

    6. Object Number: 858550 Size: SH
  6. If equipped with a 4.3L, 4.8L, or 5.3L engine, install the left exhaust manifold pipe nuts.

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


    Object Number: 665040 Size: SH
  7. If equipped with a 6.0L or 8.1L engine, perform the following:
    8. 7.1. Connect the oxygen sensor electrical connector (1).
    7.2. Connect the CPA retainer.
  8. Remove the adjustable jackstands from catalytic converter or exhaust manifold pipe.

    9. Object Number: 664951 Size: SH
  9. If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
    10. 9.1. Connect the oxygen sensor electrical connector (1).
    9.2. Connect the CPA retainer.
    9.3. Clip the oxygen sensor electrical connector to the hose clip.

    Object Number: 664828 Size: SH
  10. If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
    11. 10.1. Connect the forward oxygen sensor electrical connector.
    10.2. Connect the CPA retainer.
    10.3. Install the clip around the engine harness and the oxygen sensor pigtail.
  11. Lower the vehicle.