GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Controls - 7.4L 🢒 Catalytic Converter Replacement

Removal Procedure

    Object Number: 376934 Size: SH
  1. Remove the nuts from the catalytic converter studs.
  2. Remove the following components from the front of the catalytic converter:
    3. • The clamps
    • The U-bolts
  3. Remove the following components from the rear of the catalytic converter:
    4. • The clamps
    • The U-bolts

    Object Number: 376930 Size: SH
  4. Remove the tailpipe.
  5. Remove the catalytic converter from the muffler.
  6. Remove the gasket.

Installation Procedure

    Object Number: 376930 Size: SH
  1. Install the gasket.
  2. Install the catalytic converter into the muffler.
  3. Install the tailpipe to the converter.
  4. Install the following components to the front of the catalytic converter:
    5. • The clamps
    • The U-bolts

    Object Number: 376934 Size: SH
  5. Install the following components to the rear of the catalytic converter:
    6. • The clamps
    • The U-bolts

    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.

  6. Install the nuts to the catalytic converter studs.

    7. Tighten
    Tighten the nuts to 50 N·m (37 lb ft).