P0456 code with bad wind noise

So recently I had a check engine light come on, and when that happened I noticed a sudden decrease in fuel mileage as well as constant wind noise like my window is down. Got the code ran came back a p0456 and most likely cause is the fuel cap. I put a new fuel cap on and light didn't go away, so I re ran the code and still says fuel cap. The air sound like it's being forced in somewhere sounds like I have defrost on high and it stops when not accelerating. My question is, has anyone else had and similar situations with this being an issue, if so what were some things you did to solve the problem?

 

Did you clear the code out when you installed the new fuel cap? Have you checked under the hood for anything that may be loose, like vacuum hoses?

 

Yes I cleared code it was off till I started it. It runs good still just sounds like my defrost is on high unless I'm sitting still

 

Maybe try and get a vacuum pulled on the fuel tank? Bad fuel cap? Highly possible with the quality of some parts these days.
AND to state the obvious, are any of your windows slightly down or doors slightly ajar? Sometimes it’s the little things that we tend to miss. Just trying to cover all bases for you….

 

Just throwing out ideas….
Tire pressure ok?
Remember hitting any objects?
Any recent maintenance done by yourself or anyone else?
Any cold drafts coming in that you’re feeling? Sunroof not properly closed all the way or back window if you’ve got a slider?

 

Only thing that was done was oil, got wheels and tires last year haven't had any lights for that at all, windows are frozen shut haha but I was thinking it could possibly be because the cowl by wipers was blocked and maybe some how that's a way you get air into something

 

That is how fresh air gets into the cab, hence why some are prone to leaking. I’d still check under the hood as well, just in case something is amiss.

 

So the code popped right back on as soon as you started the truck? That's potentially an informative piece of information in and of itself I suppose, as one would expect this code to take some time to appear.

In order to diagnose what's going on a tech would use a scan tool to manually actuate the vent and purge solenoids to ensure that they are working properly (by monitoring pressure in the fuel tank). There are a whole host of different relatively minor issues that can throw this code, so a proper diagnosis is a really mandatory.