My check engine light comes on and goes off (usually on for several hundred miles then off for 50 or so). I have a fault code reader and it shows"Fd", which is evaporator shut off valve. The dealer tried: 1) replacing the carbon canister shut off valve, 2) a chck valve on the fuel tank, and 3) replacement of a breather valve. The problem persists and I replaced the gas cap after reading posts on this site. No problems with performance, just an anoying light. Anyone know how I can fix or how I can disconnect the "check engine" light.