GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Firebird 🢒 Engine 🢒 Engine Mechanical - 5.7L 🢒 Intake Manifold Replacement

Removal Procedure

    Object Number: 208459 Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information
  3. Remove the transmission fluid level indicator tube bolt.
  4. Lower the vehicle.
  5. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure in Engine Controls.

    6. Important: Cap the fittings and plug the holes when separating fuel system components in order to prevent dripping of fuel and/or dirt and other contaminants from entering the fuel system.


    Object Number: 220597 Size: SH
  6. Disconnect the fuel line from the fuel rail.
  7. Disconnect the vapor line from the fuel vapor purge valve.

    8. Object Number: 208553 Size: SH
  8. Disconnect the intake air temperature (IAT) sensor electrical connector at the air intake duct.
  9. Disconnect the mass airflow (MAF) sensor electrical connector at the air intake duct.

    10. Object Number: 208569 Size: SH
  10. Remove the air intake duct from the throttle body and the air cleaner box.

    11. Object Number: 220606 Size: SH
  11. Disconnect the idle air control (IAC) valve electrical connector from the throttle body.
  12. Disconnect the throttle position sensor (TPS) electrical connector from the throttle body.
  13. Remove the accessory drive belt. Refer to Drive Belt Replacement .

    14. Object Number: 220595 Size: SH
  14. Disconnect the exhaust gas recirculation (EGR) solenoid electrical connector.

    15. Object Number: 220596 Size: SH
  15. Remove the EGR valve pipe and solenoid.

    16. Object Number: 220601 Size: SH
  16. Unsnap the cruise control cable from the throttle lever, if equipped.
    17. • Push the cruise cable connector forward to unsnap.
    • Unsnap the cable from the engine bracket.

    Object Number: 220602 Size: SH
  17. Remove the accelerator cable from the throttle lever.

    18. Object Number: 220603 Size: SH
  18. Remove the accelerator control cable and cruise control servo bracket.

    19. Object Number: 220605 Size: SH
  19. Disconnect the right side fuel injector electrical connectors.

    20. Object Number: 220608 Size: SH
  20. Disconnect the left side fuel injector electrical connectors.
  21. Remove the fuel rail. Refer to Fuel Rail and Injectors Removal .

    22. Object Number: 220609 Size: SH
  22. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
  23. Disconnect the vacuum hose from the vacuum port on the MAP sensor housing.

    24. Object Number: 379365 Size: SH
  24. Disconnect the knock sensor harness electrical connector (4).
  25. Disconnect all the remaining electrical connections from the intake manifold.

    26. Object Number: 490736 Size: SH
  26. Remove the knock sensor harness connector (1) from the fuel rail stop bracket (2).

    27. Object Number: 379366 Size: SH
  27. Remove the positive crankcase ventilation (PCV) valve pipe from the rocker cover.

    28. Object Number: 379367 Size: MH
  28. Remove the PCV valve pipe strap nut.
  29. Remove the PCV valve pipe from the rocker cover.

    30. Object Number: 379368 Size: SH
  30. Remove the fresh air tube from the throttle body and rocker cover.

    31. Object Number: 220621 Size: SH
  31. Remove the vapor vent tube hose from the throttle body.

    32. Object Number: 220620 Size: SH
  32. Remove the throttle body heater outlet hose from the throttle body.

    33. Object Number: 220615 Size: SH
  33. Remove the evaporative emission (EVAP) canister purge tube.

    34. Object Number: 220617 Size: SH
  34. Remove the canister purge valve and bracket from the intake manifold.
  35. Remove the intake manifold. Refer to Intake Manifold Removal .

Installation Procedure
  1. Install the intake manifold. Refer to Intake Manifold Installation .

    2. Object Number: 220617 Size: SH
  2. Install the canister purge valve and bracket to the intake manifold.

    3. Object Number: 220615 Size: SH
  3. Install the EVAP canister purge tube.

    4. Object Number: 220620 Size: SH
  4. Install the throttle body heater outlet hose to the throttle body.

    5. Object Number: 220621 Size: SH
  5. Install the vapor vent tube hose to the throttle body.

    6. Object Number: 379368 Size: SH
  6. Install the fresh air tube to the throttle body and rocker cover.

    7. Object Number: 379367 Size: MH
  7. Connect the PCV valve pipe to the rocker cover.
  8. Install the PCV pipe strap nut.

    9. Tighten
    Tighten the PCV pipe strap nut to 12 N·m (106 lb in).


    Object Number: 379366 Size: SH
  9. Install the PCV valve pipe to the rocker cover.

    10. Object Number: 490736 Size: SH
  10. Connect the knock sensor harness connector (1) to the fuel rail stop bracket (2).

    11. Object Number: 379365 Size: SH
  11. Connect the knock sensor harness electrical connector (4).

    12. Object Number: 220609 Size: SH
  12. Connect the MAP sensor electrical connector.
  13. Connect the vacuum hose to the vacuum port on the MAP sensor housing.

    14. Object Number: 220608 Size: SH
  14. Connect the left side fuel injector electrical connectors.

    15. Object Number: 220605 Size: SH
  15. Connect the right side fuel injector electrical connectors.
  16. Connect all remaining electrical connectors to the intake manifold.

    17. Object Number: 220603 Size: SH
  17. Install the accelerator control cable and cruise control servo bracket.

    18. Tighten
    Tighten the accelerator control cable and cruise control servo bracket nut to 10 N·m (89 lb in).


    Object Number: 220602 Size: SH
  18. Install the accelerator cable to the throttle lever.

    19. Object Number: 220601 Size: SH
  19. Install the cruise control cable to the throttle lever, if equipped.

    20. Object Number: 220596 Size: SH
  20. Install the EGR valve pipe and solenoid.

    21. Tighten

        • Tighten the EGR valve pipe to exhaust manifold bolts to 30 N·m (22 lb ft).
        • Tighten the EGR valve pipe to cylinder head bolt to 50 N·m (37 lb ft).
        • Tighten the EGR valve pipe to intake manifold bolt to 10 N·m (89 lb in).

    Object Number: 220595 Size: SH
  21. Connect the EGR valve electrical connector.
  22. Install the accessory drive belt. Refer to Drive Belt Replacement .

    23. Object Number: 220606 Size: SH
  23. Connect the TPS sensor electrical connector to the throttle body.
  24. Connect the IAC sensor electrical connector to the throttle body.

    25. Object Number: 208569 Size: SH
  25. Install the air intake duct to the throttle body and the air cleaner box.

    26. Object Number: 208553 Size: SH
  26. Connect the MAF sensor electrical connector to the intake duct.
  27. Connect the IAT sensor electrical connector to the intake duct.
  28. Install the fuel rail. Refer toFuel Rail and Injectors Installation .

    29. Object Number: 220597 Size: SH
  29. Connect the fuel line to the fuel rail.
  30. Connect the vapor line to the fuel vapor purge valve.
  31. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information

    32. Object Number: 208459 Size: SH
  32. Install the transmission fluid indicator tube bolt.

    33. Tighten
    Tighten the transmission fluid indicator tube bolt to 50 N·m (37 lb ft).

  33. Lower the vehicle.
  34. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    35. Object Number: 208241 Size: SH
  35. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.