ok p0449 is the evaporative emissions vent solenoid circuit, either open ckt or shorted
here is the info on how to diagnose it.
Without a scantool, you would just be guessing but if you want to do that I would replace the valve and see if the issue persists. If it does, then you need a scan tool to diagnose it....hope this helps. Please click accept
DTC P0449 Battery voltage is supplied to the EVAP canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver
to replace the valve...