GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Century 🢒 Preface 🢒 Cautions and Notices 🢒 Exhaust Manifold Replacement - Right Side

Removal Procedure
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Remove the air cleaner intake duct. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.1L.
  3. Remove the accelerator and cruise control cables with the bracket from the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls - 3.1L.
  4. Rotate the engine for service access. Refer to Rotating the Engine for Service Access in Engine Mechanical - 3.1L.
  5. Remove the manifold absolute pressure (MAP) sensor. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.1L.
  6. Remove the ignition control module and the ignition control module bracket. Refer to Ignition Control Module Replacement in Engine Controls - 3.1L.

    7. Object Number: 73896 Size: SH
  7. Disconnect the heated oxygen sensor (HO2S) electrical connector.
  8. Remove the thermostat bypass pipe. Refer to Thermostat Bypass Pipes Replacement in Engine Cooling.

    9. Object Number: 190524 Size: SH
  9. Remove the exhaust crossover pipe heat shield bolts.
  10. Remove the exhaust crossover pipe heat shield.

    11. Object Number: 190525 Size: SH
  11. Remove the exhaust crossover pipe nuts from the right exhaust manifold.
  12. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  13. Remove the catalytic converter. Refer to Catalytic Converter Replacement .
  14. Remove the exhaust gas recirculation (EGR) pipe from the right exhaust manifold. Refer to Exhaust Gas Recirculation Pipe Replacement in Engine Controls - 3.1L.

    15. Object Number: 61830 Size: SH
  15. Remove the right exhaust manifold upper heat shield bolts.
  16. Remove the right exhaust manifold upper heat shield.

    17. Object Number: 61831 Size: SH
  17. Remove the right exhaust manifold lower heat shield bolts.
  18. Remove the right exhaust manifold lower heat shield.

    19. Object Number: 61923 Size: SH
  19. Remove the right exhaust manifold nuts.
  20. Remove the right exhaust manifold.
  21. Remove the right exhaust manifold gasket.
  22. Clean and inspect the right exhaust manifold. Refer to Exhaust Manifold Cleaning and Inspection in Engine Mechanical - 3.1L.

    23. Object Number: 190526 Size: SH
  23. If replacing the right exhaust manifold remove the HO2S. Refer to Heated Oxygen Sensor 1 Replacement in Engine Controls - 3.1L.

Installation Procedure

    Object Number: 190526 Size: SH
  1. If replacing the right exhaust manifold install the HO2S. Refer to Heated Oxygen Sensor 1 Replacement in Engine Controls - 3.1L.

    2. Object Number: 61923 Size: SH
  2. Install the right exhaust manifold gasket.
  3. Install the right exhaust manifold.

    4. Notice: Refer to Fastener Notice in the Preface section.

  4. Install the right exhaust manifold nuts.

    5. Tighten
    Tighten the nuts to 16 N·m (12 lb ft).


    Object Number: 61831 Size: SH
  5. Install the right exhaust manifold lower heat shield.
  6. Install the right exhaust manifold lower heat shield bolts.

    7. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 61830 Size: SH
  7. Install the right exhaust manifold upper heat shield.
  8. Install the right exhaust manifold upper heat shield bolts.

    9. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  9. Install the EGR pipe to the right exhaust manifold. Refer to Exhaust Gas Recirculation Pipe Replacement in Engine Controls - 3.1L.
  10. Install the catalytic converter. Refer to Catalytic Converter Replacement .
  11. Lower the vehicle.

    12. Object Number: 190525 Size: SH
  12. Install the exhaust crossover pipe nuts to the right exhaust manifold.

    13. Tighten
    Tighten the nuts to 25 N·m (18 lb ft).


    Object Number: 190524 Size: SH
  13. Install the exhaust crossover pipe heat shield.
  14. Install the exhaust crossover pipe heat shield bolts.

    15. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  15. Install the thermostat bypass pipe. Refer to Thermostat Bypass Pipes Replacement in Engine Cooling.

    16. Object Number: 73896 Size: SH
  16. Connect the HO2S electrical connector.
  17. Install the ignition control module and the ignition control module bracket. Refer to Ignition Control Module Replacement in Engine Controls - 3.1L.
  18. Install the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.1L.
  19. Return the engine to the original position.
  20. Install the engine mount struts. Refer to Engine Mount Strut Replacement in Engine Mechanical - 3.1L.
  21. Install the accelerator and cruise control cables with the bracket to the throttle body. Refer to Accelerator Control Cable Bracket Replacement in Engine Controls - 3.1L.
  22. Install the air cleaner intake duct. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.1L.
  23. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.