I searched and got some info, here are the particulars of my situation:
1996 M104 engine, 109k miles.
Wife stopped for gas, it was EMPTY (she got 18.2 gallons/tank capacity is 18.8 according to the manual) she topped it off, but I have instructed her not to over fill, so she says she didn't
; CEL came on as she was starting it. It runs good, no recent changes or quirks, and after the CEL came on it still runs normally. exhaust smells normal. Gas cap on tight.
I will take it to the dealer in the AM, but anybody got any ideas?
P.S can i clear the CEL myself (disconnect the battery? Would it have gone off if the condition was remedied or does it stay on till the dealer clears it??