My 2002 Dodge Grand Caravan Sport was throwing P0455, P0442, P0456 trouble codes indicating an EVAP leak. I bought a new gas cap at Advanced Auto Parts and cleared the codes out and it did not throw any codes for about a day. Then it started throwing codes again.
I wondered if a gas cap from the dealership might be a better fit. But, I read some of the post on here and decided to look at some of the hoses in the EVAP control system and the hoses going into the black canister underneath the vehicle. One of the hoses (the one with a 90 degree bend) had small cracks (like slits) in it that fed into the black canister (see attached picture). I just replaced this hose with regular gas line hose and put standard hose clamps on it. I cleared the codes and took for a test drive. So far, it is not throwing any codes yet. I will advise later if it starts throwing codes again.

 

Where do I find this Cansiter on my Dodge Caravan

 

Is my iphone messed up or did you post this question in the dodge ram 3rd gen forum? What you had was most likely a vacuum leak and could very well have been due to cracked hose.