I know that there is supposed to be pressure build up in the tank but sometimes I have very high pressure, so much that it causes gas to leak at the hose connections and I think even from the top of the tank. Seems to run down from the top of the tank also, I can't see from where of course. When I open the gas lid and release the high pressure the leaking stops. Car runs fine. So every time I drive it I open the gas lid to see how much pressure is built up and some times normal, some times very high. The carbon canister has been removed and the line to it is open to air. Any Suggestions?