GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement V8

Removal Procedure

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  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. Object Number: 1761294  Size: SH
  11. Remove the catalytic converter gasket (1). Do not reuse the gasket.

  12. Object Number: 1761299  Size: SH

    Important: Ensure the cut (1) is made 34 mm (1.3 in) from the weld on the intermediate pipe.

  13. Cut the intermediate pipe 34 mm (1.3 in) from the resonator weld.

Installation Procedure


    Object Number: 1761302  Size: SH
  1. Slide 2 service clamps (1) over the catalytic converter assembly outlet pipe.
  2. Do not tighten at this time.


    Object Number: 1761305  Size: SH

    Important: Ensure the O2 sensor boss is facing the right side of the vehicle.

  3. Slide the catalytic converter assembly (1) outlet pipe over the intermediate pipe (2).

  4. Object Number: 71703  Size: SH
  5. Place a NEW catalytic converter gasket over the catalytic converter studs.
  6. Raise the exhaust system into position, aligning the catalytic converter with the exhaust manifold pipe.
  7. Install the nuts securing the catalytic converter to the exhaust manifold pipe.
  8. Do not tighten at this time.

    Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 691380  Size: SH
  9. Install the bolts securing the center exhaust hangers to the rear suspension support brackets and tighten to 30 N·m (22 lb ft).
  10. Tighten the catalytic converter nuts to 25 N·m (18 lb ft).
  11. Remove the jack from under the vehicle.

  12. Object Number: 1761308  Size: SH
  13. Position the service clamps midway on the catalytic converter assembly outlet pipe, as close together as possible.
  14. Rotate the clamps so the fastening ends are pointing in opposite directions and tighten to 54 N·m (40 lb ft).
  15. Lower the vehicle.
  16. Check the exhaust system for leaks.