Toyota Repair: gas tank filling 2002 celica, gas station pumps, fuel filler pipe

Question
My friend has a 2002 Celica and has a problem filling up the gas tank. The filler nozzle at gas station pumps clicks off like the tank is full but it isn't. Maybe it will only put in $5 when she wants to put in $20, but it continues to click off. She says it happens at different gas stations so it is not the gas station pump. She brought it to the dealer and they checked the recall on the tank check valve. They said it is fine, but they want to change the charcoal canister for $600. Could there be a problem with it?
Thanks  

Answer
Probably not, the problem could be that something fell into the filler neck, I have seen plastic caps from fuel additive bottles or seals from the bottles in the fuel filler tubes, I have also seen parts of a gas can filler tube in there, there is something that may be lodged in the fuel filler pipe, the best way to check this before spending all that money on the evap canister, is to have the dealer remove the fuel filler pipe for inspection and make sure there are no foreign objects in the pipe or in the tank opening.