What are the reasons this thing comes on?

Car is running fine, but the light was on when I started it up just while ago.

 

Well, after doing a search... seems like it could be the charcoal canister. It's been raining like a ***** for the past two days.

Will the water problem with the canister cause any drivability problems?

 

could be a gas cap issue too. try tightening that first bring to autzone for a free scan.

 

yeah, did that the right when I got home after noticing the light. It's one of the things that causes the same light to go off on our Ford Lightnings. I did fill up the car yesterday, so thought that might be it. Guess I'll see if it goes off tomorrow... otherwise, I'll disconnect the battery when I get home from work.

 

also it might be time to clean your MAF sensor don't disconnect the battery just pull the EFI fuse

http://groups.msn.com/Sorensonbrian/...rcleaning.msnw

 

probably gas cap