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Throttle body mechanism

Please tell me what the throttle body mechanism is all about and what the recommended maintenance is. I have a 2003 Toyota Highlander, V-6, with 42,500 miles on it.



Also, do you recommend the cleaning of the fuel injectors, and if so, what is the recommended method of cleaning them. Is it an additive used in the engine oil and flushed out, drained and refilled with clean oil and at what mileage intervals should it be done?



I am a 63 year old semi retired truck driver who METICULOUSLY maintains his vehicles I am very satisfied with this vehicle. It has been very reliable and has a very “cushy” and carlike ride.



Thank you.

Don’t know what type that has but normally not much needed unless there is a problem. Maybe once a year with the Seafoam treatment ingested through a vacume line and cleaning the throttle and bore with O2 sensor safe throttle bore cleaner.

The throttle body mechanism controls the amount of air that is allowed to enter the engine. It is connected to the accelerator pedal. The fuel injectors match their flow of fuel to match the flow of air allowed by the throttle body to provide power.

Generally, there is no real service period for the throttle body. I check the throttle body on my vehicles on every plug change, which is about every 4-5 years with the factory-style platinums. I open the throttle flap by hand, and inspect the back side of the plate for carbon build-up. If significant build-up is there, I clean it out with a SENSOR-SAFE throttle body cleaner.

The only time I’ve removed a throttle body to clean it was one that had a huge amount of carbon build-up, and the engine’s problem maintaining a decent idle. The IAC (Idle Air Controller) motor is generally attached to the throttle body so the computer can adjust the idle speed. Those ports were also so gunked up, the IAC had a hard time maintaining idle.

If it ain’t broke, don’t fix it. Plain old good fuel will keep the injectors clean.

The owner’s manual for your Highlander will tell you if there’s any maintenance needed on the throttle body. My guess is that none is needed.

ALL gasoline has fuel system detergents included, by federal law. You should not need to clean the fuel injectors under normal circumstances, despite all the adds trying to sell fuel injector cleaner. It’s not necessary.

Additives of any kind are to be avoided. They are not needed, usually don’t do anything, and can potentially make things worse.

Your Highlander should have come with a maintenance schedule. Read and follow it.