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My 2002 es300 with 108k miles is shuddering when warm and at idle. When the engine is cold, i don't notice it only when it is warm at signal I get vibrations. don't see any other issues, it runs smooth accelerates nicely.

I am suspecting throttle body. Never done this so to clean it, do I have to remove air filter box? or can I just open clamps and pull ducts? Any other word of advice?





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At that mileage you may indeed require a throttle body cleaning, the idle air control valve (IAC) may require replacing or cleaning, but most assuredly you need new spark plugs. I would suggest both are required.

Since the rear 3 spark plugs against the firewall require the intake manifold to be removed in order to get at them to change them, the throttle body can be easily cleaned up, because it will already be free of the top of the engine. The IAC will be easy to get at as well.

There are YouTube videos showing throttle body cleaning, as well as the intake manifold removal for spark plug change. Check out the IAC cleaning/replace videos as well. Anyone used to wrenching on cars can do both jobs, but if its not your cup of tea, any good independent mechanic can do the job a lot cheaper than the dealership. Use the same NGK iridium plugs that Lexus used from the factory. They'll inject new life into the car with performance that you hadn't realized that you had lost over the years. Good Luck!



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