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Q: It has a slight rough idle

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Felt like a misfire, so I replaced plugs and wires. The issue was still there with idle dropping a little low after giving it gas and just a rough in general. Took it to a friend with a scanner because it had a check engine light on and the code was for cylinder #8 misfire. I swapped the coil to the #2 cylinder and then took it back to read but no CEL on. I did a vacuum test and it was at 18in hg and went to 21in hg at 2000 rpm. I took PCM fuse out turned key to start until I heard two chimes and then reinstalled. No CEL on and it drives great but when it's stopped, the idle is slightly rough. It's pretty minor, but it's not smooth like it was before.

My car has 11000 miles.
My car has an automatic transmission.

A: You may have fixed the misfire, but the rou...

You may have fixed the misfire, but the rough idle may be due to clogged injectors and carbon build up on the valves. Try cleaning injectors and throttle body and intake system and see if problem improves. If you the problem still persists, you may want to enlist the help of a certified mechanic, such as one from YourMechanic, to come to your car and inspect the rough idle.

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