I have a 05 Optima with about 24000 miles on it. EVERY time we fill it up no matter how much we put in, it has major hesitation once we began to drive off. it is so bad that i can be pushing the gas pedal to the floor, trying to pull out onto the highway and it will just stop on me after moving 2 feet. now after about 30 seconds it runs perfect like always and will never happen again until i fill up again. i have no proof at all but i feel that it might have something to do with pressure in the gas tank, but i have checked the gas cap to make sure it was on tight. ANYONE ELSE WITH THIS PROBLEM? HELP!?!?