I never did on my 08 PLB after two years. The guy that got a code had 187K and never had a light come one before the dealer worked on his car As long as you're not forcing the fuel into the filler neck, it should never be able to enter the canister.
That's what I'm trying to see. I never had a code on my 01 saturn and it has almost 200k miles on it. I force the fuel into it, too. I don't on my PC, but that's more because I'm lazy and the car will go more than 150 miles farther than the saturn.
When I say forced, I'm talking about keeping the nozzle in the filler neck. I DON'T DO THAT. I pull the pump nozzle out of the tank and allow the fuel to gravity fill down into the neck until it fills the tank up to the top. No pressure/force from the pump nozzle.
Same with our Prius, 2 gallons to the top after first auto click off. I don't do it all the time only in states I can pump my own gas, Oregon you can't legally pump gasoline into your car, but in all the other surrounding states it is lawful. The extra 2 gallons in your Priuc C should give you a comfortable 500 mile plus tank range...
