I filled up a couple days ago and i wasn't paying attention and i over filled my gas tank. Since, my check engine light comes on every once and a while. Some times it stays on for the entire drive and sometimes it stays on for about five minutes. I am down to about 1/4 of a tank and its still doing it. Has any one ever had this problem. It could have been a bad batch of fuel but I am not too sure. Any info would be appreciated.

 

Pull the codes and see what is stored:

http://www.fd3s.net/engine_codes.html

 

I found the problem. The code was 16. The EGR valve. It says its for California only. Any idea what the EGR valve is?

 

EGR = Exhaust Gas Recirculation valve. Here's some links to two from Autozone....this is just for you to gauge the price, which isn't really cheap, I recommend ordering them from Ray at Malloy Mazda (keep it in the Mazda loop)

Without Cali. Emission:
http://www.autozone.com/R,APP470232/...ductDetail.htm

With Cali. Emission:
http://www.autozone.com/R,APP470234/...ductDetail.htm