we have a 99 beetle 2.0L automatic. our check engine lite will go on n it will stay on for about a week or so then turn off for about a day or 2 then turn back on again. ill scan it and get misfire codes for cylinder 1,2,3,n 4. so ill delete them n everything will be fine for a couple days till the lite comes back on and its the misfiring codes again. we replaces the coil pack 3 times already along with the plugs n wires. and its still giving us the misfiring codes. the car has 156,000 miles on it. if the timing belt is stretched could it be giving us the misfiring codes? if not please HELP !!!!!!!!!!!!!!!

 

You can start diagnosing from here http://www.automd.com/diagnose/qna?aid=413&option=1, hope it helps you in a way..