Im new to to this site. I a 2003 Hemi with a K&N intake, Airaid throttle body spacer, Borla dual side exhaust. Yesterday the check engine light came on and would not reset.I went to the local auto store and rented a diagnostics tool the one that you plug in under the dash. I read the following: Evap emission controll system leak P0456 very samll leak. I was wondering if anyone out there has had this problem or heard about it and how to fix it. The last thing i added was the exhaust its been on about 2 weeks. The K&N intake and the spacers been on about 9 moths never had this code come up until now.

 

check your gas cap and make sure it seats well...close with at least 3 clicks. if not that then check your vac lines and evap canister

 

Look under your truck in front of the gas tank. You'll see your evap canister/system. Check the rubber hoses in that set up. Those have rotted on a # of trucks causing evap codes.

And as said above, ensure your gas cap is on good.

 

mine did the same thing a couple days ago. Guy said it was probably the gas cap, but I don't think thats what it was. I will the hoses you mentioned. I hate Check Engine Lights....... sigh.

 

Check the gas cap. I have seen it a few times with friends.