
Originally Posted by
Drinkey McDrinkerstein
It could be a lot of different things. Most of the time, that light functions to alert for emissions issues, most of which shouldn't affect how the car operates. Sometimes, as you said, it's simply the gas cap being loose, and for some models it just does that when it needs an oil change. It's always good to get the code read just in case it's on because there's a leak somewhere that could cause serious damage.
i've had chronic problems with the sensors that cause the light to come on. They've been fixed for some time now, but it was a pain in the butt to keep getting them fixed to pass smog tests.