DTC P0442: EVAP Control System, Small Leak Detected: Condition

WARNING: This page is about a different car, the 2002 Mazda Protege5 and 2002 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when PCM detects excessive difference in fuel tank pressures measured immediately after purge control is stopped and preset period of time has elapsed. This is monitored when following conditions are met:

Fuel tank pressure is .34-1.15 in. Hg.
Fuel remaining is 35-85 percent of total capacity.
Intake air temperature is 14-140°F (-10-60°C) and engine coolant temperature is 14-95°F (-10-35°C) when engine is first started.
Atmospheric pressure is more than 20.5 in. Hg.
Vehicle speed is 24.5-74.7 MPH.
Engine speed is 1000-4000 RPM.
Calculated load is 9-65 percent.
Throttle opening angle is 3.1-12.5 percent.

This is an intermittent monitor. MIL is illuminated when PCM detects malfunction during 2 consecutive drive cycles. Possible causes are:

Purge solenoid valve malfunction.
Canister Drain Cut Valve (CDCV) malfunction.
Fuel pressure control valve malfunction.
Loose or defective fuel filler cap.
Charcoal canister malfunction.
Catch tank malfunction.
Rollover valve malfunction.
Cracked fuel tank.
Poorly installed fuel tank components.
EVAP hoses damaged or loose.