I keep getting code P0457. It starts with the gas cap light then eventually the engine light. I replaced the gas cap with one from AutoZone, reset the code, but two days later it came back. Any help would be appreciated.



2003 Taurus, 24v DOHC, 36000 miles

 

Some vehicles may exhibit a Malfunction Indicator Lamp (MIL) illuminated with Diagnostic Trouble Codes (DTCs) P0442, P0455, P0456, P0457 or P1442 or a "Check Fuel Cap" Lamp illuminated with DTC P0457 for the Evaporative Emission System. This may be caused by loose or leaking hoses, loose or broken fuel cap, a leak at the top of the fuel filler pipe neck, a faulty purge valve, FTP sensor and etc. Has the vehicle been back up or bottomed out over something that tagged the vapor canistor? I believe that the vapor canistor sets under the vehicle just behind the fuel tank.

 

Not that I know of but then again my wife drives it so it's possible. It doesn't look like anything has hit it, no dents or scrapes. My wife admitted shetries topping off the tank each time she fills up. I heard this may cause a problem also.It doesn't look like anything is leaking fuel. If it is a valve or sensor are they easy to get to and change?

 

Haven't replaced any of these items on a Taurus. I would try driving the vehicle for a while andwhen filling the tank, stop when the pump shuts off. See if that does anything for you. I have a 2000 Taurus with the DOHC and always fill it to the rim and have never had any fuel related codes set. I just may be lucky, or you just may have a failed part. Anyway,your emission systemmay still be under warranty depending on what the item is and if your vehicle has California emissions.

California Emissions System
Required on units for California, Maine, Massachusetts, New York and Vermont registration. Optional for Arizona, Connecticut, Nevada, New Hampshire, New Jersey, Oregon, Pennsylvania and Rhode Island (Cross-Border States).

Hope this helps.