This has also happened to me a few times in the year that I have owned the car-it's an '06 w/ 139k on it now(130k when we bought it)-I clear it,and it usually doesn't come back on for a few months-of course it came on a couple weeks ago,cleared it,now my car won't pass inspection here in NY(evap. system and catalyst not ready)-this is after 2 weeks of driving......