I have a 2002 WRX that has 106,000 miles on it and also has had a three inch exhaust system straight to the turbo with out cats, a STI intercooler, a trubo timer and a hallman boost controller as its mods. About 3 or 4 months back I had a Subaru dealership put on a new fuel line because the stock one was faulty and it would leak gas fumes in cold weather when I started the car. I also had belts and spark plugs changed out at 100,000 miles by a different service station. It ran very well up intil a week ago...it would not maintain an idle...it would crank over, sputter and die and I could smell gas. I took it to a service station and they started it right up and it ran like a top. They kept it for a week and couldn't get it to show any symptoms that I had experienced. I got the car back and drove it and it ran great. I try to start it today and it showed the same symptoms as before. The symptoms seem to come and go...what could cause that?