Do you stop fueling when the nozzle clicks the first time, our do you "top off" a few times?
Always stop fueling when the nozzle shuts off the first time. Continuing to fuel after that overfills, and allows the fuel to slosh up the filler neck, allowing raw fuel to enter into the charcoal canister, damaging it. Its intent is to capture the fumes only.
If this is not the case, it could be the fuel filler "flap"; these model years do not have a gas cap, but rather a flap in its filler neck.
It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.