My car just two days ago started acting funny. Every once in a while when i have a steady low rpm drive going(like in cruise contorl) in primarily 2nd or 3rd gear my car will start to studder and rock back in forth sometimes rather violently. Just today my check engine light came on. At first i thought i might have water in my gas but i have filled it with a tank and a half and it still does it. The only thing i can think of is something to do with the fuel line. Anyone have similar problems or any of you car geniuses know whats going on? Thanx for the help guys!