GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Replacement - Left Side RPO LD8

Removal Procedure

Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.


    Object Number: 1665455  Size: SH
  1. Remove the front engine mount bracket. Refer to Engine Front Mount Bracket Replacement .
  2. Remove the connector position assurance (CPA) retainer.
  3. Disconnect the engine harness electrical connector (3) from the heated oxygen sensor (HO2S).

  4. Object Number: 1670526  Size: SH
  5. Remove the HO2S.

  6. Object Number: 1670489  Size: SH
  7. Remove the exhaust manifold front pipe bolts (2).

  8. Object Number: 1670472  Size: SH
  9. Remove the exhaust manifold bolts.
  10. Remove the exhaust manifold (2).
  11. Remove and discard the exhaust manifold gasket (1).
  12. Remove and discard the front exhaust manifold pipe seal.
  13. Remove the front exhaust manifold pipe flange.

Installation Procedure


    Object Number: 1670472  Size: SH
  1. Install the front exhaust manifold pipe flange and a NEW seal onto the exhaust manifold.
  2. Insert the upper right exhaust manifold bolt to the manifold in this location (2).
  3. Place the NEW exhaust manifold gasket over the bolt and against the manifold.
  4. Insert the exhaust manifold into the front exhaust manifold pipe and against the cylinder head.
  5. Finger start the exhaust manifold bolt.
  6. Notice: Refer to Fastener Notice in the Preface section.

  7. Install the remaining exhaust manifold bolts and tighten all exhaust manifold bolts starting from right to left beginning with the bolt in this location (2).
  8. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).


    Object Number: 1670489  Size: SH
  9. Install the exhaust manifold front pipe bolts (2).

  10. Object Number: 1670526  Size: SH
  11. If reusing the old HO2S, coat the threads with anti-sieze compound, GM P/N 12377953 or equivalent.
  12. Install the HO2S.
  13. Tighten
    Tighten the sensor to 41 N·m (30 lb ft).


    Object Number: 1665455  Size: SH
  14. Connect the engine harness electrical connector  (3) to the HO2S.
  15. Install the CPA retainer.
  16. Install the front engine mount bracket. Refer to Engine Front Mount Bracket Replacement .

Exhaust Manifold Replacement - Left Side RPO L26

Removal Procedure

Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.


    Object Number: 1686528  Size: SH
  1. Remove the oil level indicator and tube. Refer to Oil Level Indicator and Tube Replacement .
  2. Disconnect the spark plug wires from the spark plugs.
  3. .

  4. Remove the spark plug wire channel from the rocker cover.

  5. Object Number: 1686626  Size: SH
  6. Remove the engine harness clip (1) from the engine lift bracket.

  7. Object Number: 1686527  Size: SH
  8. Remove the engine lift bracket bolt and nut.
  9. Remove the engine lift bracket.

  10. Object Number: 1688415  Size: SH
  11. Remove the 2 bolts attaching the exhaust crossover to the left exhaust manifold.

  12. Object Number: 1688304  Size: SH
  13. Remove the exhaust manifold heat shield bolts and shield.

  14. Object Number: 1688303  Size: SH
  15. Remove the exhaust manifold bolt, studs and nuts.
  16. Remove the exhaust manifold.
  17. Remove and discard the exhaust manifold gasket.

Installation Procedure


    Object Number: 1688303  Size: SH
  1. Install a NEW exhaust manifold gasket onto the studs.
  2. Install the exhaust manifold.
  3. Notice: Refer to Fastener Notice in the Preface section.

  4. Install the exhaust manifold nuts, studs and bolt.
  5. Tighten
    Tighten the bolt, studs, and nuts to 30 N·m (22 lb ft).


    Object Number: 1688304  Size: SH
  6. Position the exhaust manifold heat shield to the manifold.
  7. Install the exhaust manifold heat shield bolts.
  8. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 1688415  Size: SH
  9. Install the 2 bolts attaching the exhaust crossover to the left exhaust manifold.
  10. Tighten
    Tighten the bolts to 18 N·m (13 lb ft).


    Object Number: 1686527  Size: SH
  11. Install the engine lift bracket.
  12. Install the engine lift bracket bolt and nut.
  13. Tighten
    Tighten the bolt/nut to 25 N·m (18 lb ft).


    Object Number: 1686626  Size: SH
  14. Install the engine harness clip (1) to the engine lift bracket.

  15. Object Number: 1686528  Size: SH
  16. Install the spark plug wire channel to the rocker cover.
  17. Connect the spark plug wires to the spark plugs.
  18. Install the oil level indicator and tube. Refer to Oil Level Indicator and Tube Replacement .