My check engine light came on some time ago.. I had it checked and the engine code was P1456...and i was told to fix the evaporative 2 way valve.. and my gas cap.. both were done.. light still on. From my understanding, there are many things it could be. The light is intermittent.. sometimes stays on for a month.. then goes off for a week or 2.. then comes back on..etc. Very weird...i'm getting sick of looking at the light because i need to know what it is, but don't feel like getting ripped off at the dealer. Is there a common part for this engine code that fixes the problem? Any help would be great!!! thanks!