GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Servicing of the mufflers, resonator or pipe requires the replacement of the exhaust system as a complete 1-piece unit.

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.

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement .
  3. Disconnect the heated oxygen sensor at the pigtail.
  4. Remove the heated oxygen sensor if replacement is necessary. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 in Engine Controls-4.6L.

  5. Object Number: 71703  Size: SH
  6. Remove the 4 nuts securing the catalytic converter to the rear exhaust manifold pipe.
  7. Remove the catalytic converter gasket. Do not reuse the gasket.
  8. Suitably support the exhaust system.

  9. Object Number: 691380  Size: SH
  10. Remove the 2 bolts securing the center exhaust hangers to the rear suspension support brackets.

  11. Object Number: 722483  Size: SH
  12. Remove the 2 bolts securing the rear exhaust hanger brackets to the rear compartment rails.
  13. With the aid of an assistant, lower the exhaust system.

  14. Object Number: 722383  Size: SH
  15. Remove the 2 nuts securing the rear exhaust hangers to the rear exhaust hanger brackets.
  16. Remove the rear exhaust hanger brackets from the rear exhaust hangers.

Installation Procedure


    Object Number: 722383  Size: SH
  1. Install the rear exhaust hanger brackets to the rear exhaust hangers.
  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.

  3. Install the 2 nuts securing the rear exhaust hangers to the rear exhaust hanger brackets.
  4. Tighten
    Tighten the rear exhaust hanger nuts to 30 N·m (22 lb ft).


    Object Number: 71703  Size: SH

    Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

  5. Place a NEW catalytic converter gasket over the catalytic converter studs.
  6. Notice: Do not over-flex or damage the flex joint when moving the flex joint from the normal mounting position.

  7. With the aid of an assistant, raise the exhaust system into position, aligning the catalytic converter with the rear exhaust manifold pipe.
  8. Finger tighten the 4 nuts to the catalytic converter studs.

  9. Object Number: 722483  Size: SH
  10. Install the 2 bolts securing the rear exhaust hanger brackets to the rear compartment rails.
  11. Tighten
    Tighten the rear exhaust hanger bolts to 50 N·m (37 lb ft).


    Object Number: 691380  Size: SH
  12. Install the 2 bolts securing the center exhaust hangers to the rear suspension support brackets.
  13. Tighten
    Tighten the center exhaust hanger bolts to 30 N·m (22 lb ft).

  14. Tighten the 4 catalytic converter nuts previously installed in step 5.
  15. Tighten
    Tighten the catalytic converter nuts to 25 N·m (18 lb ft).

  16. Install the heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 in Engine Controls-4.6L.
  17. Remove the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement .
  18. Lower the vehicle.