GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1263045  Size: SH

    Notice: Do not over-flex or damage the flex joint when moving the flex joint from the normal mounting position.

    Notice: To prevent internal damage to the flexible coupling of the catalytic converter assembly, the converter must be supported. The vertical movement at the rear of the catalytic converter assembly must not exceed 6 degrees up or down.

  1. Remove the exhaust manifold heat shield bolts and the heat shield.

  2. Object Number: 1263670  Size: SH
  3. Remove the auxiliary catalytic upper flange nuts.

  4. Object Number: 1263627  Size: SH
  5. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  6. Remove the auxiliary catalytic converter lower flange nuts and ring type from the inlet/outlet flange of the auxiliary catalytic converter gasket.
  7. Remove the auxiliary catalytic converter.

Installation Procedure


    Object Number: 1263627  Size: SH
  1. Install the auxiliary catalytic converter.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the auxiliary catalytic converter lower flange nuts and ring type to the inlet/outlet flange of the auxiliary catalytic converter.
  4. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).


    Object Number: 1263670  Size: SH
  5. Install the auxiliary catalytic upper flange nuts.
  6. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).


    Object Number: 1263045  Size: SH
  7. Install the exhaust manifold heat shield bolts and heat shield.
  8. Tighten
    Tighten the bolts to 15 N·m (11 lb ft).