The CEL usually means one or more emission control modules are faulty. Start by getting an inexpensive OBD scanner online. About $50 for stand alone handheld but only about $25 for one which requires a laptop such as ELMScan 5 (amazon). The codes you get, especially after 6 mos should be suspect but write them down and clear all the codes. Drive for a few days and then rescan. Those are the codes to consider. FYI- Be sure NOT to clear codes just before a smog inspection or you'll get a 'status not ready' error from the smog tester and have to return.

Ignoring a CEL can get expensive. For example, a bad MAF can cause an over rich mixture which in time will kill your CATs.

__________________
Good luck.






1998 E320 Wagon