ok... so, i have an 09 Aveo and every now and then the check engine light comes on, i would take the car to my mechanic. first time it came on, i had the MAP sensor changed. no problems for a few months, light came on, bad ignition coil, whole pack replaced. no problems for many more months. light came on again, mechanic says misfire. car runs strong still, though it has an erratic idle. like when i get to my destination and park, when i put it into park, the engine will rev on its own up to about 2000-2300 rpm and come back down to just below normal and stay there. and when im in traffic, it seems to have delayed upshifts. but all this has resulted in my AC not working. i cant even feel the compressor kick on or the engine note change. this is a problem as i live in Texas and the summer heat is fast approaching. also, there is a small opening on the valve cover, just under the plastic lid that covers the ignition coil pack. i can hear and feel air rushing in. i dont remember seeing/hearing this before, but my mechanic put a small piece of plastic wrap on the hole to keep air from being sucked in. i dont notice any change with or without the plastic over the little hole. i cant find anything on these things on the internet yet. HELP!!!