Removal Procedure

Fig 1: Fuel Injector Wiring Harness Connectors

Courtesy of GENERAL MOTORS CORP.

Important:  The fuel injector wiring harness connectors must be connected to their respective fuel injectors. Failure to connect the fuel injector connectors to their respective fuel injectors may result in excessive exhaust emissions and poor engine performance.

1. Drain the engine coolant from the cooling system. Refer to DRAINING AND FILLING COOLING SYSTEM .
2. Remove the throttle body air inlet duct.
3. Remove the accelerator control and cruise control cables with bracket from the throttle body.
4. Disconnect the wiring harness connectors from the following throttle body components:
   • Throttle Position (TP) sensor
   • Idle Air Control (IAC) valve
5. Disconnect the engine left side spark plug wires. Refer to SPARK PLUGS .
6. Disconnect the engine left side spark plug wire harness attachment clip. Refer to SPARK PLUGS .
7. Disconnect the throttle body heater hoses. Refer to THROTTLE BODY HEATER HOSE REPLACEMENT - INLET and THROTTLE BODY HEATER HOSE REPLACEMENT - OUTLET .
8. Disconnect the vacuum hoses from the evaporative emission (EVAP) canister purge solenoid valve.
9. Remove the EVAP canister purge solenoid valve. Refer to EVAP CANISTER VENT VALVE .
10. Remove the ignition coil bracket.
    Fig 2: Ignition Coil Bracket

    Courtesy of GENERAL MOTORS CORP.
11. Disconnect the wiring harness from the manifold air pressure (MAP) sensor.
    Fig 3: Wiring Harness AT Manifold Air Pressure Sensor

    Courtesy of GENERAL MOTORS CORP.
12. Disconnect the vacuum harness from the MAP sensor and the upper intake manifold.
    Fig 4: Vacuum Harness At MAP sensor

    Courtesy of GENERAL MOTORS CORP.
13. Disconnect and remove the emission control vacuum harness.
Fig 5: Emission Control Vacuum Harness
Courtesy of GENERAL MOTORS CORP.
14. Disconnect the vacuum brake booster hose from the upper intake manifold. Refer to POWER BRAKE BOOSTER CHECK VALVE AND/OR HOSE REPLACEMENT .
15. Disconnect the vacuum hose connections from the upper intake manifold.
    • Heating, ventilation and air conditioning (HVAC) vacuum source hose
    • Fuel pressure regulator
16. Remove the exhaust gas recirculation (EGR) valve. Refer to EGR VALVE .
17. Remove the MAP sensor and the bracket. Refer to MANIFOLD ABSOLUTE PRESSURE SENSOR .
18. Remove the upper intake manifold studs and bolts.
    Fig 6: Upper Intake Manifold Studs & Bolts

    Courtesy of GENERAL MOTORS CORP.
19. Remove the upper intake manifold.
    Fig 7: Upper Intake Manifold

    Courtesy of GENERAL MOTORS CORP.
20. If you are REPLACING the intake manifold, remove the throttle body. Refer to THROTTLE BODY .
    Fig 8: Throttle Body Assembly

    Courtesy of GENERAL MOTORS CORP.
21. Remove the upper intake manifold gasket.
Fig 9: Upper Intake Manifold Gasket
Courtesy of GENERAL MOTORS CORP.
22. Clean and inspect the upper intake manifold.