Thanks for the replies so far. I haven't really paid attention to how full the tank is when the light comes on, but I did fill up this morning. I'll pay attention today when I go home. I saw another thread from some time ago about possibly the charcol canister going bad? I need to get this fixed as we do have emissions checks here in the Salt Lake City area, otherwise I'd not worry about it. I'd rather do it myself since I'm not a big fan of the local MB dealership.