I have a 07 Ram 5.7 Hemi I have 2 codes coming up PO440 and PO456 also have GASCAP message on dashboard odometer. I had a EGR valve code about a month ago replaced EGR all was good last week check engine light came on and about 3 days later the GASCAP message appeared now I am showing the codes above any ideas where to start. Thanks

 

You have a leak in your EVAP system. The fuel tank isn't holding pressure. Could be the gas cap not sealing or a hose around canister above the tank.