Need help!! got code P1456

[JonathanPrem]

Do i need to replace my gas cap or is there something more important. It start popping up after i forgot to close my gas cap.

Please tell me this is a cheap fix.

[Densetsu]

It's indicating a loss of pressure in the EVAP system, usually from a loose or old gas cap. Reset the code and then be diligent about tightening the gas cap at least three clicks. If it comes up again, then the next step I'd take would be to buy a new gas cap. Best bet is an OEM cap from the dealer, random aftermarket ones are usually hit-and-miss.

If that's not it, then there's a leak somewhere else in the system and that's when it gets fun. It's a huge PITA to find a tiny little leak in an EVAP system. This won't really affect performance or mileage, you just have your CEL light on. Still, that alone would drive me crazy. I hate warning lights on my dash.