I have a 2008 Maxima and it is throwing a P0456 code. I noticed it a few months ago after smelling gas and setting it slowly drip from the back of the car. I kind of just left the car in my garage since then because my wife and I just finished building a house but I just broke her out for the first time since February 6th yesterday. The code just returned this morning but there is no gas leaking....yet. I haven’t smelt the gas yet either so I’m really at a loss with what it could possibly be with so many things that could be wrong. I’ve attached a video from when it was leaking in February. Any and all help/suggestions would be most appreciated.

 

New gas cap and purge valve didn't fix it?

 

On my 2008, code I got was on the Evap system, a mass air leak. Changing fuel cap didn't help. I did notice there didn't seem to be any press in the fuel tank after releasing the fuel cap. It was a faulty canister vent valve stuck open.