GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Park Avenue 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Exhaust System Replacement

Removal Procedure

    Object Number: 105359 Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove four nuts from the catalytic converter to the exhaust downpipe.

    3. Object Number: 104986 Size: SH
  3. Remove the oxygen sensor heat shield.
  4. Remove the oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls.

    5. Object Number: 284269 Size: SH
  5. Remove the two nuts and bolts securing the center exhaust hanger to the body.

    6. Object Number: 390768 Size: SH
  6. Remove the rear exhaust hanger attachment to rail.
  7. Remove the exhaust system.

Installation Procedure

    Object Number: 390768 Size: SH
  1. Install the exhaust system.

    2. 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.

  2. Install the rear exhaust bracket to the underbody.

    3. Tighten
    Tighten the rear exhaust nuts to 50 N·m (37 lb ft).


    Object Number: 284269 Size: SH
  3. Install the center exhaust hanger to the exhaust.

    4. Tighten
    Tighten the exhaust hanger nuts to 27 N·m (20 lb ft).


    Object Number: 104986 Size: SH
  4. Install the Oxygen sensor. Refer to Heated Oxygen Sensor Replacement in Engine Controls.
  5. Install the oxygen sensor heat shield.

    6. Object Number: 105359 Size: SH
  6. Install the four nuts to the exhaust downpipe to the catalytic converter.

    7. Tighten
    Tighten the nuts to 24 N·m (18 lb ft).

  7. Lower the vehicle.