Ok so a couple days ago I noticed that when I'm sitting at idle my engine starts idling very rough and you can hear and feel what feels like a bumping noise, not overly loud or anything.. And like I said it idles rough.. also when at idle if I step on the throttle a lil bit the rpms rise and then hang there for a few seconds and then come back down (example if I raise the rpms to 1500 they will stay there for a few seconds, if I take it from 15 to 2000 it will hang there for a few seconds).. these problems disappear though when I actually drive off, it's only at idle that they occur.. The only thing I did to the car was late last week I filled up with Sunoco 94 octane premium.. Could I have gotten some bad gas or is it the octane is too much for my car? Also I took it to AutoZone to have it scanned because my CEL came on but when they plugged into the diag port it didn't initialize the scanner so they couldn't give me any codes. Any help is vastly appreciated.. :SNSign: :SNSign: