What is the fault code P 0442 for 2000 Durango with check engine light on?

It means "Evaporative Emission Control System Leak Detected (small leak)" What that means is a tiny leak in the fuel evap system, most likely the gas cap. Remove and reinstall the gas cap (past the clicks) and clear the code. If the code comes right back, check the hoses leading to the charcoal canister near the gas tank under the truck for wear. My '99 Durango throws this code about twice a year, I just clear it and it's good to go for about 6 months. This code will never affect the drivability of the truck, It's just there for pollution purposes, like most OBD-II codes. Good Luck! See this; http://www.obd-codes.com/trouble_codes/generic/p0442-evaporative-emission-control-system-leak-detected-small.php