I have a 100k mile stock GT thats been giving me trouble. I have had to DD it for a couple of months after my truck got hit by a moving truck. I feel like these problems must be intertwined... 1) Poor gas mileage 2) Gas smell after driving for awhile 3) Gas cap hisses at me for an extended period when I unscrew it 4) Impossible to fill up without the gas splashing out at me... it should trigger the nozzle to stop sooner 5) Hard to start, takes about three times... but this may be the starter going out on me I don't know much about the EVAP system so that's what I'm trying to learn about currently. I had a shop in East Atlanta Village replace the sending unit and they didn't raise any concerns about the condition of the tank or connections when they had it out. These problems started before then but I wasn't driving it daily so it was easy to ignore.