Dean,
I don't believe that there should be an open vent line??? The Evap system is a closed system for that purpose...to keep any fuel vapors from escaping into the atmosphere.
There was a recall of 2003 model Sport Tracs because a vent hose was a little too short and would come loose...that would allow water, dirt, road debris, and probably insects into the evap system. The solution was to add a short plastic elbow and reattach the hose. This problem appears to not give a CEL, so you would never know unless you see the hose dangling by the rear wheel well. If the vapor canister was damaged, they supposed to replace it, followed by the hose mod.
I had a 2003 and got a recall letter for this problem. At the time I was working ar a Ford dealership so I had the shop look at it while I was working. Mine was not disconnected, but they still did the elbw mod as required.
It sounds like your 2003 never made it in for the recall, and your vent hose came loose from the evap canister... I don't know if they would fix it under the recall after 12 years?? But it might not be a bad ideat to ask....you might get a new evap canister..:grin:
...Rich