2008 Subaru outback 2.5 with 105K code P0457. What would be most likely cause?
I have changed gas cap and checked purge valve because it is easy to get to.(I have physical limitations) It seems to work but does not hold vacuum on the evap side if more than a few inches of mercury is applied. I don't know how much vacuum is used. I fear the canister will need to be replaced but it is expensive.Do I really need to pay someone with a factory scan tool to diagnose this and what if they are wrong? I still have to pay again. Thanks