Check engine light???

[KeysRam]

Well last night i washed my truck got her all nice this morning i got up and was going to the stor i got in and it started fine when i was backing up i noticed the check engine light i figured it should be fine i started down the road and the engine was about to die and shake rpms were droping and going up so i put it in park and reved it so i went back home checked it there was watter under the hood i got my tester and it said P0456 Evap Leak Monitor Small (0.020) Leak Detected any idea what it could be

 

[OlDirtyJohn]

Check your gas cap, evap canister, and the lines going to it.

 

[KGBIGCOUNTRY]

Yep John has got it. Normaly its the gas cap acting funny but the evap lines are a close second.

 

[KeysRam]

alright thanks guys i erased the light and tightened everything so hope it wont come on again