I did run over an opossum shortly before the light went off. Maybe it hit something and knocked it loose. The only reason I didn't think anything of it was because it gave me an O2 sensor error as well (which isn't currently there). I guess I was thinking that since this guy fixed it when there wasn't any leaks, it could be the same situation:
http://www.renntech.org/forums/index.php?showtopic=23455&pid=124869&st=0&#entry124869