Hey guys I'm pretty new to this forums but I need some help. I read through every post regarding the CEL code P0457(emissions evap. Fuel Cap loose). I have a 2004 WRX with a turbo back exhaust, and cobb accessport with stg 2 93 octane. I have checked the gas cap and seal, and then replaced both the cap and seal, checked the black box under the car and found no loose lines, checked the vacumm lines next to the alternator and no luck. My CEL will come on about 50 to 60 miles after a fill-up, and go off about a half a tank or just under. I don't top it off, I go just to when the nozzle kicks off the first time. I have tried to fill it to 3/4 of a tank and it still comes on and then goes off when its under a half a tank. I haven't had the fuel pump ever changed and I don't smell any sort of fuel fumes with the exception of during fueling of course. If anyone has any other ideas please help.