FixVault
Home › Buick › 2004 › Century Custom › Repair and Diagnosis › Engine Mechanical › Engine Exhaust System › Repair Instructions › Catalytic Converter Replacement (3.8L) › Installation Procedure

Installation Procedure

    Fig 1: View Of Catalytic Converter Mounting Nuts
    GM212193Courtesy of GENERAL MOTORS CORP.
  1. Install the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Position 2 in Engine Controls - 3.8L.
    2. NOTE: 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.
  2. Install a new gasket to the exhaust pipe studs.
  3. Install and support the 3-way catalytic converter.
    4. NOTE: Refer to Fastener Notice in Cautions and Notices.
  4. Install the catalytic converter nuts.

    Tighten:  Tighten the nuts to 60 N.m (44 lb ft).

    5. Fig 2: View Of Catalytic Converter & Exhaust Manifold Pipe Stud Nuts
    GM372626Courtesy of GENERAL MOTORS CORP.
  5. Install a new exhaust manifold pipe gasket.
  6. Install the exhaust manifold pipe stud nuts.

    Tighten:  Tighten the nuts to 35 N.m (26 lb ft).

    7. Fig 3: View Of Catalytic Converter Hangers
    GM289493Courtesy of GENERAL MOTORS CORP.
  7. Install the catalytic converter hangers.
  8. Remove the support from the exhaust system.
  9. Connect the heated oxygen sensor (HO2S) electrical connector.
  10. Inspect the exhaust system for leaks and underbody contact.
  11. Lower the vehicle.
About FixVault