2003 Tiberon. Cant always get gasoline to go in the tank ; theres anoccasional hissing/exhaust soun

Any idea what might be causing these anomolys ? Whats preventing me
from adding gasoline in order to fill the gas tank ? Many thanks.

 

Could be any sort of restriction preventing fuel from entering the
tank or vapors from venting.

Presuming there's no restriction on the path for fuel to enter, the
most likely culprits are a clogged canister filter, stuck closed
canister close valve, and liquid fuel in the charcoal canister.

 

Thanks much.