GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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. Support the exhaust system near the resonator with a suitable jack.
  3. Remove the oxygen sensor. It is not necessary to disconnect the electrical connector.

  4. Object Number: 71703  Size: SH
  5. Remove the nuts securing the catalytic converter to the exhaust manifold pipe.

  6. Object Number: 691380  Size: SH
  7. Remove the bolts securing the center exhaust hangers to the rear suspension support brackets.
  8. Remove the catalytic converter from the manifold pipe.
  9. Lower the exhaust system.
  10. Remove the catalytic converter gasket. Do not reuse the gasket.

  11. Object Number: 908799  Size: SH

    Important: Ensure the cut (2) is made on the catalytic converter side of the pipe.

  12. Cut the catalytic converter (3) from the resonator inlet pipe (1) behind the step 2 but as close to the step as the tool will permit. The replacement catalytic converter will slide over the inlet pipe.

Installation Procedure


    Object Number: 908804  Size: SH

    Important: Use care not to over extend the heated oxygen sensor pigtail.

  1. Lower the exhaust system only enough to install the catalytic converter to the resonator inlet pipe (1).
  2. Important: Ensure the solid portion of the catalytic converter heat shield is upward.

  3. Slide two service clamps (2) over the catalytic converter outlet pipe (3).
  4. Do not tighten at this time.

    Slide the catalytic converter outlet pipe (3) over the resonator inlet pipe (1), until fully seated against the heated oxygen sensor boss.


    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. Raise the exhaust system into position, aligning the catalytic converter with the exhaust manifold pipe.
  8. Install the nuts securing the catalytic converter to the exhaust manifold pipe.
  9. Do not tighten at this time.

    Notice: Refer to Fastener Notice in the Preface section.


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

  12. Tighten the catalytic converter nuts.
  13. Tighten
    Tighten the catalytic converter nuts in a crisscross pattern to 25 N·m (18 lb ft).

  14. Remove the jack from under the vehicle.
  15. Important: Ensure the catalytic converter outlet pipe is fully seated against the heated oxygen sensor boss.

  16. Position the service clamps midway on the catalytic converter outlet pipe, as close together as possible.
  17. Rotate the clamps so the fastening ends are pointing in opposite directions.
  18. Tighten
    Tighten the service clamps to 30 N·m (22 lb ft).

  19. Lower the vehicle.
  20. Check the exhaust system for leaks.