I have a 2004 Nissan Xterra with the 3.3L V6 approximately 143,750 miles I am getting the p1456 code as well as the p0442 code it’s for my emissions system.
Recently replaced following parts
Evap canister
Evap canister valve
Evap purge valve
Evap hoses
Clamps
Fuel cap
Fuel filter.
Abunch others as well but they have nothing to do with this problem I don’t think at least. I’m still getting the codes thrown no matter how many times I’ve erased them. I still get a slight fuel smell but only when it throws the code again.
There is special equipment to help find evap system leaks, you could buy this equipment or pay a shop $100 to diagnose the leak.
I actually have already taken the Xterra to a local Firestone and they told me it was the evap canister so I had that replaced yet I’m still getting the same problem I was.
The charcoal canister was a poor guess, I rarely find the canister leaking. You may need to have a shop with more skill than the Firestone tire dealer to find the leak.
I’ll definitely have to give it a try then was hoping that I wouldn’t have to do that again