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 Cooling System Draining and Filling in Engine Cooling.
2. Remove the throttle body air inlet duct. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.4L.
3. Remove the accelerator control and cruise control cables with bracket from the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.4L.
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 Plug Wire Replacement in Engine Electrical.
6. Disconnect the engine left side spark plug wire harness attachment clip. Refer to Spark Plug Wire Replacement in Engine Electrical.
7. Disconnect the throttle body heater hoses. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in Engine Cooling.



8. Disconnect the vacuum hoses from the evaporative emission (EVAP) canister purge solenoid valve.
9. Remove the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.4L.



10. Remove the ignition coil bracket.



11. Disconnect the wiring harness from the manifold air pressure (MAP) sensor.



12. Disconnect the vacuum harness from the MAP sensor and the upper intake manifold.



13. Disconnect and remove the emission control vacuum harness.
14. Disconnect the vacuum brake booster hose from the upper intake manifold.
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 MAP sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.4L.
17. Remove generator through bolt bracket.



18. Remove the upper intake manifold studs and bolts.



19. Remove the upper intake manifold.



20. If replacing the intake manifold, remove the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.4L.



21. Remove the upper intake manifold gasket.
22. Clean and inspect the upper intake manifold. Refer to Upper Intake Manifold Cleaning and Inspection in the Engine Unit Repair Manual.

1. If removed, install the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.4L.



2. Install the upper intake manifold gasket.



3. Install the upper intake manifold.



4. Install the MAP sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.4L.

Notice: Refer to Fastener Notice in the Preface section.

5. Install the upper intake manifold studs and bolts.

Tighten
Tighten bolts to 25 N·m (18 lb ft.)

6. Install generator through bolt bracket.
7. Connect the vacuum hose connections to the upper intake manifold:

•	Heater and air conditioning vacuum source hose

•	Fuel pressure regulator

8. Connect the vacuum brake booster hose to the upper intake manifold.



9. Install and connect the emission control vacuum harness.



10. Connect the vacuum hose to the MAP sensor and the upper intake manifold.



11. Connect the wiring harness to the MAP sensor.



12. Install the ignition coil bracket with the coils.
13. Install the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.4L.



14. Connect the vacuum hoses to the EVAP canister purge solenoid valve.
15. Connect the throttle body heater hoses. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in Engine Cooling.
16. Connect the engine left side spark plug wire harness attachment clip. Refer to Spark Plug Wire Replacement in Engine Electrical.
17. Connect the engine left side spark plug wires. Refer to Spark Plug Wire Replacement in Engine Electrical.
18. Connect the wiring harness connectors to the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.4L.
19. Install the accelerator control and cruise control cables with bracket to the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.4L.
20. Install the throttle body air inlet duct. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.4L.
21. Fill the cooling system with engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.