hi trev, eliot, machine and dogs- will look for that lever behind the speedometer which shuts off the light and whether it causes the light to go out. have read someof the O2 sensor posts here. unless ive missed something the obd 1 does not specify O2 sensor fault.uncle moe says all it does is list a plethora of possible suspects. is it true that if it is bad, it kicks the computer to make the fuel mixture rich. now if that is also true wouldnt that have to noticeably turn the mpg stinko. my mpg remains excellent . just trying to catch the perpetrator of this fault and eliminate it w/o going to the cleaners(dealer). admit my bad attitude , but like donald apologize for nothing. thanks tons oldduke