Hi guys, I have a 98 civic ex with:A High flow cat, 2" performance muffler, headers, cold air intake, stage 2 clutch, short shift, and I moved the intake behind my passenger side tire. When my car is at idle, it moves up and down, also if I roll up the windows, it effects the idle. I have a 500 watt amp, and 12" subs, that are 500 watts. I have a 1 fared capacitor, and I don't think the system is effecting the idle. Even if my deck is off, it won't idle correctly. My original alternator started to fail, so I replaced it, and I had my battery tested, and that is fine too. Sometimes the car will idle right at 900(where its supposed to) and other times it won't. I cleaned my throttle body, and my idle control thing. I cannot figure out what would be causing this. Has anyone had the same issue?? Any ideas??

 

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