GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Replacement LLR

Removal Procedure

Warning: Refer to Exhaust Service Warning in the Preface section.

Warning: Refer to Protective Goggles and Glove Warning in the Preface section.


    Object Number: 858158  Size: SH
  1. Remove the secondary air injection (AIR) check valve. Refer to Secondary Air Injection Check Valve Replacement.
  2. Remove the exhaust seal. Refer to Exhaust Seal Replacement.
  3. Remove the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement.
  4. Remove the exhaust manifold bolts.
  5. Remove the exhaust manifold.

  6. Object Number: 858159  Size: SH
  7. Remove and discard the exhaust manifold gasket.
  8. Clean and inspect the exhaust manifold. Refer to Exhaust Manifold Cleaning and Inspection.

Installation Procedure


    Object Number: 858159  Size: SH
  1. Clean and apply threadlock GM P/N 12345493 (Canadian P/N 10953488) to the exhaust manifold bolt threads.
  2. Position a NEW exhaust manifold gasket onto the cylinder head.

  3. Object Number: 858158  Size: SH
  4. Position the exhaust manifold against cylinder head.
  5. Install the exhaust manifold bolts.
  6. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 858367  Size: SH
  7. Tighten the exhaust manifold bolts.
  8. Tighten

    1. Tighten the bolts a first pass in sequence to 20 N·m (15 lb ft).
    2. Tighten the bolts a second pass in sequence to 20 N·m (15 lb ft).
    3. Tighten the bolts a final pass in sequence to 20 N·m (15 lb ft).
  9. Install the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement.
  10. Install the exhaust seal. Refer to Exhaust Seal Replacement.
  11. Install the AIR check valve. Refer to Secondary Air Injection Check Valve Replacement.