Hey everyone, I know that p0440 is a common and usually a small evap code. Changed the gas cap, no help. One thing I noticed is that when I remove the gas cap to fill up, no suction noise! I have a ton of small vacuum hoses under the hood that are beginning to crumble, have been replacing one at a time. My canister seems to be in good shape . My understanding is that my cab would stink of fumes if my canister was bad. Another Thu.g I noticed is a lot of condensation dripping from tail pipe and about mid way under truck. But that hole suction thing when I remove the gas cap really caught my attention. Any ideas greatly appreciated.

 

Bump? I have the exact same problem after changing my fuel pump

 

One of the most definitive ways of diagnosing a small EVAP leak is by doing a smoke test. It isn't something that everyone can do in their driveway though...

antman94, if the problem surfaced after changing the fuel pump, it stands to reason that somehow things did not seal back up properly during reassembly.