I have a 1999 Chevy Venture I just had the oil changed a month ago and now the oil light comes on. I checked for leaks, none, then I checked the oil and it is fine, the light has been on for the past 2 days and today it went off while I was driving, when I shut the van off and restarted it, it stayed off, what could be the issue? The only thing I can think of is the oil pressure sensor?? Anyone else have a clue?