the light comes on every 90,000 miles to remind you to change the 02 sensor. it has no diagnosis or failure notification duties.

even better than switching that stupid screw from one hole to another, just take out the bulb for the 02sensor idiot light so you don't have to do it again in 90,000 miles <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> that's what i did...now that's old school.

to get to the back of the instrument cluster find and remove the 8 or so screws holding the outside trim piece (that surronds the insturments,radio,ashtray, cdplayer,etc) and remove it as you disconnect the a few wire connectors from the backside as you go. then remove the obvious screws for the instrument cluster and pull it out.

do you need to put a new 02 sensor in there? how old is it. if it's original it's probably not a bad idea, but it's up to you if you want to wait until it starts showing failure symptoms -- like failing smog check. some say 02 sensors degrade over time short of failure and affect performance and fuel mileage....

good luck
//bc