I went to autozone and then ran a test on the code reader. I got back the P0303 or whichever one is the third coil. I tested the coil by pulling each cover off and testing the difference of each on the engines sound, no difference. So now I think it might be the spark plug on the third coil position? The car is a 2003 honda civic with 140k on it. Spark plugs haven't been changed as far as I know, bought this car used.
What do you think?
Thanks
Added (1). What I meant was that each time I removed a cover I heard a difference, so I've crossed out the ignition coils as a culprit.
Read more: Misfiring car? Not sure what to do next?
