Subaru Problems? Ask a Mechanic for Answers ASAP
Good afternoon, Remove the large hose between the tank and the canister at the canister, now blow into the canister. Air should exit the drain hose with no restriction. Try filling the gas tank while the large hose is off, if the tank still can't be filled without the pump shutting off, there is a problem with the rollover check valve on the top of the fuel tank. The drain valve is build into the canister located inside the vehicle in front of the spare tire.
So either you have a restriction you can clear our bad evap canister or check valve. Included are steps to replace the evao canister. Thanks.