Hyundai Repair: 2002 HYUNDAI ELANTRA, hyundai elantra, fuel vapors

Question
The "CHECK" light is on and I can't put fuel in tank because it trows it out like if it is already full.
what could be the possible cause of the gas tank throwing out the fuel?

Please help
Thanks!

DR

Answer
Presuming that you have code P0446 or P0449, you have a problem with being able to properly vent fuel vapors through the charcoal canister.  The most frequent issues are a clogged canister or canister filter, or a stuck shut canister close valve.  Although less likely, a restriction anywhere else in the vent circuit between the tank and atmosphere could also be the issue.