Hello, I have a 2012 g37x with 83 500 miles. I’ve had this p0456 code for a few months now. I’ve changed the gas cap with the oem one from z1 Motorsports and I’ve replaced the evap canister that is located at the charcoal canister. My engine light is still on after replacing both of those parts. Any idea what the issue can be?

 

Mine was doing g rhe same thing and I found the return vent tube just behind the gas filler tube had rusted out right at the bracket mount. They discontinued the part so you'll have to Mackey mouse a fuel line in. Check it out. It's most likely the same problem I've got and it's a nightmare

 

I had this, didn't do anything other than opened and closed fuel cap, and cleared the code. Yours is probably more serious..

 

Definitely check it any ways. Because it's a factory flaw and it's just a matter of time.
let my situation be the canary in the mine. It's hard to find and I first noticed it when the gas cap didn't make the hiss sound anymore. I said oh well it must be just the weather. Then a month later the code came on and I went and got the gas cap and then the purge valve lile YouTube said but low and behold it turned out to be the fuel vent return line rusting out at the holding bracket. Check it and make sure before it gets too far and too late and when you fill up and gas starts leaking.