No, as odd as this sounds, we've been getting the PO 440 code on and off for around a year. Ever since i decided to try to let the gas run very low to see if there is a warning light that would let you know when you get down to the last gallon. Up until then, we had no trouble. What happened was, i would let the tank run low... no -low fuel- warning light would come on, and then i would get nervous about running out, and get gas. i finally put a small can of gas in the car, so i wouldn't worry about it, and instead of a low fuel warning light coming on, the cel came on instead -at least that's how it seems. Ever since then it as spent pretty much time on. The local mechanic i use read the code, checked what he knew to look for and advised me to make sure i keep the gas cap tight. He's looked under there a few times, and has never noticed a problem. We discovered the pin hole leak, because one time i went to the store (which is very close to the gas station) right after filling it, and gas was leaking on the parking lot.
i will have my husband and brother (a GM mechanic) check the evap system -hoses, etc - and actually also read them your post.
My brother has been thinking it might be the pressure sensor, but he is unfamiliar with the Subaru system (and -whenever i have a problem with my car- is always making snarky comments about Subarus).
Do you know where the pressure sensor is?
---neilinda (linda)