you can access the code through the hvac controls, info is in this link
http://myweb.accessus.net/~090/dtcobd1.html
these cars have some issues with the fuel pump wires, melting and making poor connections,
also you might try replacing the fuel filter , since its an easy one to do, and could cause your issues
having the pressure in the tank is not unusaul, my 94 will build up as well, mostly on 1/4 tank or less, follow the instructions and see if you pull up any codes, then let us know
http://myweb.accessus.net/~090/dtcobd1.html
these cars have some issues with the fuel pump wires, melting and making poor connections,
also you might try replacing the fuel filter , since its an easy one to do, and could cause your issues
having the pressure in the tank is not unusaul, my 94 will build up as well, mostly on 1/4 tank or less, follow the instructions and see if you pull up any codes, then let us know