DTC P0455: EVAP Control System Large Leak Detected: Condition

WARNING: This page is about a different car, the 2002 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when a substantial leak has been detected in evaporative emission system. Possible causes are:

Purge solenoid valve malfunction.
Canister Drain Cut Valve (CDCV) malfunction.
Loose filler cap.
Charcoal canister malfunction.
Catch tank malfunction.
Pressure control valve malfunction.
Cracked fuel tank.
Poorly installed fuel tank components.
Evaporative hoses damaged or loose.
Low manifold absolute pressure.
Fuel tank level sensor malfunction.
Fuel Tank Pressure (FTP) sensor malfunction.
Engine Coolant Temperature (ECT) sensor malfunction.
Intake Air Temperature (IAT) sensor malfunction.
Throttle Position (TP) sensor malfunction.
Mass Airflow (MAF) sensor malfunction.
Vehicle Speed Sensor (VSS) malfunction.