GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Riviera 🢒 Engine 🢒 Engine Exhaust 🢒 Exhaust Manifold Replacement

Removal Procedure

    Important: Note the position of the rear pipe (Y-pipe) prior to servicing.

  1. Support the resonator.
  2. Remove the oxygen sensor. Refer to Converter Heat Shield Replacement Engine Controls.

    3. Object Number: 71751 Size: SH
  3. Remove the nuts retaining the converter to the exhaust manifold rear pipe.

    4. Object Number: 71755 Size: SH
  4. Remove the bolts that retain the rear pipe to the exhaust manifold.
  5. Remove the bolts that retain the rear pipe to the crossover pipe.
  6. Remove the exhaust manifold rear pipe.

Installation Procedure

    Object Number: 71755 Size: SH

    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.

  1. Install the bolts to the exhaust manifold.

    2. Tighten
    Tighten the exhaust manifold flange bolts to 30 N·m (22 lb ft).

  2. Install the bolts to the crossover pipe.

    3. Tighten
    Tighten the crossover pipe bolts to 30 N·m (22 lb ft).

  3. Install the converter seal.

    4. Object Number: 71751 Size: SH
  4. Install the converter nuts.

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

  5. Install the oxygen sensor. Refer to Converter Heat Shield Replacement Engine Controls.