I keep getting a code po440 from evap and I changed the purge solenoid already on 2003 Chrysler 300M

and lite keeps coming on
after a month

Asked by for the 2003 Chrysler 300M
May have small leak in evap hoses between tank and purge valve. Kind of difficult to find on your own but try and follow line between. If not, may want to seek service whereas they can pump a smoke through line to try and locate if leak exists. Could have blockage too in evap canister.