Pontiac Repair: 2003 Pontiac Montana, pontiac montana, pontiac

Question
Check engine light came on today and the van runs really rough while idiling and driving. Very noticeable once vehicle is started.

Answer
Hey Blaine:


It can be a lot of things it may be a a misfire but not severe enough that the service engine light has come on or the light is flashing. when the light starts to flash it's severe enough to cause catalitic converter damage. it could be a rich or lean running issue making it run rough. My guess it's it's misfiring now what can cause it?? it can be a bad plug wire or a dirty injector.. It's really hard to say for sure what's going on without seeing it. good luck :}