GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Pipe Replacement 3.5L (L66)

Removal Procedure

  1. Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle .

  2. Object Number: 1236197  Size: SH
  3. Remove the oil pan bracket (2) and bolts (1, 3).

  4. Object Number: 1237806  Size: SH
  5. Remove the exhaust pipe flange to the catalytic converter nuts (3) .
  6. Remove the exhaust pipe to mid muffler pipe nuts.
  7. Remove the front exhaust pipe.
  8. Fully remove and discard the used gaskets.

Installation Procedure

Notice: Excessive flexing of the exhaust pipe may damage the flex coupling. Limit flexing to 12 degrees.


    Object Number: 1237806  Size: SH
  1. Position pipe into vehicle, and install new gaskets onto converter studs.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Assemble exhaust pipe to converters, install new nuts and tighten .
  4. Tighten
    Tighten the nuts to 18 N·m (13 lb ft).

  5. Install the new gasket (1) onto the exhaust pipe rear flange.

  6. Object Number: 926814  Size: SH
  7. Assemble the front pipe to rear pipe, install the nuts and tighten.
  8. Tighten
    Tighten the front pipe-to-rear pipe nuts to 30 N·m (22 lb ft).


    Object Number: 1236197  Size: SH
  9. Install the oil pan bracket (2) and bolts (1, 3) and tighten.
  10. Tighten
    Tighten the bolts to 20 N·m (14 lb ft).

  11. Lower the vehicle. Refer to Lifting and Jacking the Vehicle .
  12. Start the engine and check for exhaust leaks.

Exhaust Manifold Pipe Replacement L61

Removal Procedure

Caution: Ensure that the vehicle is properly supported and squarely positioned. To help avoid personal injury when a vehicle is on a hoist, provide additional support for the vehicle on the opposite end from which the components are being removed.

Notice: Excessive flexing of the exhaust pipe may damage the flex coupling. Limit flexing to 12 degrees.


    Object Number: 927920  Size: SH
  1. Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Important: Do not apply silicon products to the oxygen sensor.

  3. Disconnect the electrical connector from the oxygen sensor (O2S).

  4. Object Number: 926819  Size: SH
  5. Remove the nuts from the exhaust pipe flange to intermediate pipe and separate the flange from the studs.

  6. Object Number: 898154  Size: SH
  7. Remove the nuts from the exhaust pipe flange to exhaust manifold.

  8. Object Number: 926825  Size: SH
  9. Separate the hanger from the rubber isolator.
  10. Separate the pipe flange from the manifold studs and remove the exhaust pipe.
  11. Fully remove and discard used gaskets.
  12. Remove the oxygen sensor if transferring to a new exhaust pipe.

Installation Procedure


    Object Number: 898154  Size: SH
  1. Install a new gasket onto the exhaust manifold studs.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Assemble the exhaust pipe to manifold. Install new nuts and tighten.
  4. Tighten
    Tighten the nuts to 42 N·m (31 lb ft).


    Object Number: 926819  Size: SH
  5. Install the new gasket onto the exhaust pipe flange.
  6. Assemble the exhaust pipe to intermediate pipe. Install new nuts and tighten.
  7. Tighten
    Tighten the nuts to 30 N·m (22 lb ft).

  8. Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  9. Start the engine and check for exhaust leaks.