If you are getting the timing belt skipped a tooth code, then I would definitely check the timing belt. After I replaced the timing belt on mine, the code came on for a skipped tooth. Turns out that we didn't recompress the timing belt tensioner and that caused the problem. My neon didn't seem to exhibit the problems that yours is though. I know that it is a bit*@ to get back in there, but its worth it if it solves the problem. Good Luck.