Hello and Happy Friday keepers of the Lexus faith!

If you need to replace the intake manifold (or even just replace the gasket) then you could use a thorough walk-through on the procedure. Well, today is your lucky day because I am sharing a DIY article on the procedure!

--Helpful diagrams--
Lexus LS430 Manifold diagram



1. Properly relieve the fuel system pressure.

2. Remove or disconnect the following:
Negative battery cable
Engine under cover
Coolant
V-bank cover
Air cleaner assembly and connectors
Throttle body assembly

3. Disconnect the fuel inlet hose (rear fuel pipe) from the fuel main tube.

4. Remove and disconnect the following:
VSV connector for EVAP
EVAP hose from VSV
VSV from upper intake manifold
4 V-bank cover brackets
Engine wiring protector (LH side) from the upper intake manifold and camshaft bearing cap
2 wire clamps (RH side) from the brackets on the delivery pipe
Engine wire protector (rear side) from the rear water bypass joint and the RH cylinder head
VSV connector for the ACIS
8 injector connectors

5. Remove the 6 bolts and 4 nuts and remove the upper and lower intake manifold assembly.

6. If necessary, the upper intake manifold can be disassembled from the lower intake manifold by removing or disconnecting the following:
Vacuum hose for VSV from air control valve actuator
Vacuum tank hose from lower intake manifold
Vacuum hose (VSV for ACIS) from clamp
Wire clamp from lower intake manifold
Vacuum tank and VSV assembly from ACIS
Air control valve actuator
15 bolts and 5 nuts to remove upper intake manifold from lower intake manifold

To install:

NOTE: Always be sure to use new gaskets at each component mounting.

1. Reassemble the upper and lower intake manifold in reverse of disassembly procedure given. Torque the upper intake manifold-to-lower manifold bolts and nuts to 13 ft. lbs. (18 Nm).

2. Install the vacuum tank and VSV assembly. Torque the nuts to 13 ft. lbs. (18 Nm).

3. Reconnect all of the wiring connectors, clamps and vacuum hoses in reverse of the removal procedure.

4. With new gaskets on the cylinder heads (white marks facing outward), position the upper and lower intake manifold assembly into position. Install the 6 bolts and 4 nuts and torque them to 13 ft. lbs. (18 Nm).

5. Reinstall and reconnect all remaining components in reverse of the removal procedure.

6. Refill the cooling system. Start the engine and check for leaks and proper operation.