hello all...today i changed out my spark plugs, radiator fluild, changed my oil, and also changed out my fuel filter. i started to the car after i was done and let it run for about 10 minutes and it sounded great. later tonight i took the car for a drive and everything seem smooth but after about 10 minutes, the car would sputter or something like it was miss firing. when i'm idle at a stop sign, it also sputter. what can be the problem so i could work on the problem tomorrow morning? thanks for you guys help.