Q: After a fuel injector/throttle body cleaning, my Idle goes up and down constantly in park. When in gear it doesnt.

asked by on November 21, 2017

Had my throttle body/ fuel injectors cleaned and now when my car is in park the idle goes from 2000 rpms back to normal , constantly up and down. Like I'm constantly reving my engine, but I'm not. They said it has to burn off the chemical and then it would stop. Is this true? or did they mess something up? When it's in gear or a/c on it's fine. Please help.

My car has 114000 miles.
My car has an automatic transmission.

Hi DeShon. Thanks for contacting us today. Usually, when a mechanic cleans a throttle body and fuel injectors with a chemical additive, it’s seafoam; which can be rather harsh on sensors and other fuel system components. This is often the cause of higher RPM after using this stuff (which I never recommend). It will take some time for the chemical to work its way through the fuel system. In some cases, you’ll have to remove the idle control valve and manually clean it, if excess carbon ’gunk’ sticks on this part. Give it a week or so, and if this issue does not improve, you’ll want to have a different mechanic inspect the Nissan for you.

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