[Airjer_]

check the vent solenoid. with it unplugged you should be able to blow through it. If you supply power and ground it should close and you should not be able to blow through it. Also make sure there is 12 volts to the solenoid with the key on. There is a separate fuse just for this and I have had many of them blown.

The other option is there is a problem with the Fuel Tank Pressure sensor. Unlikely but possible.