To remove the intake manifold, first relieve the fuel system pressure and disconnect the cable from the negative battery terminal. Next, remove the air intake duct and resonator, followed by the cowl cover assembly. Then, take out the fuel rail and injectors as an assembly. For models from 1999 to 2007, remove the throttle linkage and throttle body from the intake manifold, label and detach the PCV and vacuum hoses connected to the intake manifold, and securely support the vehicle on jackstands. If working on a 4WD model, loosen the right side driveaxle/hub nut and the right front wheel lug nuts before raising the vehicle. Drain the transfer case lubricant, remove the right side driveaxle, and separate the transfer case mount from the transfer case, removing the transfer case mounting brace. For all models, work below the vehicle to remove the manifold lower mounting bolts, then from above, remove the intake manifold upper mounting nuts and bolts, and take out the manifold, gasket, and manifold insulator from the engine. For models from 2008 and later, remove the engine cover, disconnect the vacuum hoses and ventilation tubes from the intake manifold, and remove the throttle body with the electronic throttle actuator. Additionally, remove the windshield wiper motor, brake booster vacuum bracket, and outer cowl top assembly, then disconnect and remove the main harness connector to the intake manifold and tumble control valves. Apply battery voltage to the tumble control valve electrical connector to close the valve, preventing damage during removal. Remove the intake manifold support bracket and disconnect the vacuum switching valve assembly electrical connector, then unscrew the intake manifold mounting fasteners and remove the manifold. For installation, clean the mating surfaces of the intake manifold and cylinder head mounting surface, checking the gasket for leaks and the manifold for warpage. Press a new gasket into the grooves on the intake manifold, install the manifold and gasket over the studs on the cylinder head, and tighten the manifold-to-cylinder head nuts/bolts in three or four equal steps from the center outwards. Reinstall the remaining parts in reverse order, check the coolant level, refill the transfer case for 4WD models, and ensure the throttle linkage operates smoothly before starting the engine to check for coolant and vacuum leaks.
Posted by LexusPartsNow Specialist 
