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I have an after market cat back exhaust and headers on my 2000 Honda civic ex. The car runs fine and doesn't have any issues besides the idle. It seems that the car will idle fine then when I stop it will sort of sputter and then catch back up to a normal idle. Any idea what is causing this?
Note:I don't have a cat after I put the aftermarket exhaust on. Just a straight pipe. Aldo I had to modify the o2 sensors in the straight pipe because it kept throwing a code. I used a spark plug non-fowler to pull it out of the exhaust stream a bit. No more check engine light.