thats a large leak. under your car where the gas filler neck is, get under the car look up, you'll see the fat gas filler tube and another smaller line with it, the small one likes to rust out. its the tank vent tube. see if its wet with gas after a fill up too.
i had the same code forever, i got a tuner and deleted it, so i never gave a crap no more. till i smelt gas after a fill up and found this tube rusted in two and hanging under the car. i rigged it back together with rubber hose, but im sure it was the cause of my evap code.
