The tank on my 98 seems to be pressurized when it is not running. Fuel is leaking from clamps on the filler neck, even after a couple hours when I remove cap it hisses. Leak stops once tank has been vented, any ideas? I am used to working on Suzuki Sidekicks...

 

The tank is designed to build up some pressure while stopped. This prevents unburned gas vapors from escaping into the air, which is a major cause of smog.

Excess pressure is supposed to be relieved through the "three way valve" on top of the tank to the vent line, which goes up front to the EVAP canister under the hood. The charcoal in the canister traps any vapors coming out of the vent until the engine is started again.

Trouble with the EVAP system is rare. It could just be that the rubber hoses are degraded or the clamps are loose and the connections can't withstand normal pressure.