car runs well but idles poorly coming back to idle after stopping, condition worse with a/c on.well maintained, all emission and electronic engine controls still original.have checked for vacumn leaks and all is well-i think!
My car has 100000 miles.
My car has an automatic transmission.
You will need to run a Check Engine Light scan. I suspect that you will have a problem with the EGR valve stuck partly open causing the internal vacuum leak and a rough idle. You can remove, clean, and reinstall the valve. If it still leaks then replace the valve.
If you need some help getting this fixed, feel free to contact a certified mechanic who can diagnose your rough idle and make any repairs that are necessary.
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