no, the way it was explained to me is - every 90,000 miles the o2 light comes on no matter what. the switch is just for turning that off. disconnecting battery cleared any "stored" codes.after that any codes you get are active and need to be addressed. in my case i just purchased the vehicle and did this to start from scratch. generally i'm not that lucky, so i'm gonna take one while i can get it <img src="/forums/images/graemlins/smile.gif" alt="" /> hth- mike <img src="/forums/images/graemlins/cheers.gif" alt="" />

ps- in some vehicles the check engine light comes on every so many miles. i'm curious if anyone knows if 1st gen troopers do this as well, and if so is it reset the same way?