when my car is idling it has a random poping sound, almost like its spitting. if i hold it at 2000rpm it sounds like a misfire, but i unplugged each COP one by one and could tell they were all fireing. its done this since i have owned it, and it only has 52k on the car. i have the diablosport tune on it. there are no codes, but it seems to be running very rich(it stings my eyes if i sit near the exhaust) any ideas??