P0456 from loose gas cap?

[cabinpath]

Hey

The check engine came up and autozone said it is P0456 and that my gas cap was loose... and it sure was. I guess the fuel pump guy didn't close it correctly because it was not closed propertly...

Anyway, once I closed it it's been two weeks but I still have the check engine light.. It won't go away by itself?

Can it be something else?

[disallow]

As far as I recall, it should go out when you restart 3 times.

But short of that, have the autozone guy just clear the code. Usually if you leave the code reader plugged in for a few cycles it clears it.

[eieio]

pretty sure the P0456 code can also be related to the emissions canister, hoses, and valving

[08PathPounder]

I had the same code, dealer ship did a smoke test and said my canister needed to be replaced.... I called bullshit. (Bought my Nissan from a Chevy dealership and they are a true "stealers hip") After lowering my spare to put in my air lift bags I took a gander at the canister which is on the driver side in the rear fender/bumper ish area... I noticed a little dirt in a pinhole size hole in the canister... I literally blew in it to clear the dirt and have not had the code come on again since. Been a few thousand miles with no issues or codes. My advice to you: give it a look and see if you can tell what's up.

[smj999smj]

I would erase the code and see if it comes back. If it comes back, it is more than likely the vent control valve on the canister. I believe there was a couple of TSB's on it. One was an updated filter kit for the vent control valve and the other was for an updated vent control valve, which has a bigger solenoid to close the valve harder.