I have a 1999 Subaru Outback Legacy. I started to see the CEL light come on about 4 weeks back. I took it to autozone and they scanned it as P0440. I made sure my gas cap was tight and reset the error. After about an hour of driving, the light came back again.
This time I replaced the gas cap and reset the error. Just like last time, the error came back (and I confirmed that it was the same code) again.
The guy at Autozone said I could have a leak in my hoses and recommended I buy the Carb cleaner and spray each of the fuel carrying hoses to see if I can identify a broken hose. He said if there is a leak, I would hear the engine rev up.
Let me know if you think this is the way to diagnoze the problem further. I searched some stuff online and the Purge valve came up as a possible cause.
All suggestions are welcome.
Thanks in advance Ravi