[Ulitaco]

Did you fix the small evap issue?

 

[Ulitaco]

FOUND THE LEAK

I bought a smoke tester and connected it to the EVAP service port! No smoke anywhere. Let it run for about 10 minutes and didn't see a whisp of smoke anywhere. I ran around the truck 20 times with a flashlight looking EVERYWHERE. But no smoke.
But then I heard an odd sound under the passenger rear seat.
Got under there and heard a hissing coming from the fuel tank but didn't see any smoke. So... started spraying the the tank with soapy water and would'ja look'it that? Found the leak coming from the fuel pump!
Are the pumps serviceable? Any o-rings that can be replaced? Or is this a full pump replacement? :/

Also, I really wanna know why there was no smoke... when I removed the gas cap, smoke poured out. So the system was definitely full of smoke, but it wasn't coming out of the leak. Any ideas? Would the smoke end up going through the charcoal canister first before filling the tank? Maybe the charcoal filter captured the smoke.... but that also just doesn't make much sense because the pump would still be in the same cavity (gas tank) as the filler neck. And the filler neck has smoke in it so that means the tank had smoke in it but none was coming out of the leak. Maybe it was but I just couldn't see it because it's such a small leak. I dunno.

Before you do anything with the pump. Did you change out the vent valve to the newer version already? I know from your older posts that the one you had was an older version. Id change that if you havent yet. Its what fixed my problem after a gas cap change didnt help and the dealership performed a smoke test twice for me with no results. My code would go off at random times after a reset so I figured my vent valve was probably sticking also it was quite rusted so I just went ahead and replaced it and the code hasnt come back since.

Personally I feel if it had anything to do with your pump and if the leak is similar to the video you linked it would trigger a code much bigger than just a “very small leak” code.

When you did the smoke test did you also connect to the obd port beforehand? I believe there is a step you have to do to set the vent valve and purge valve to the proper positions for the test before introducing smoke into the system. You must do this to be able to properly identify a leak. I believe youd need like a mid level obd2 tester to do this cause i dont think the cheapo ones have the smoke test option.

 

[Ulitaco]

I haven't. I just keep clearing the code..I think it's a permanent code now.

What have you done to attempt to fix the issue so far?

I was able to fix my P0456 code by replacing the vent valve. Id do that first before taking it in for a smoke test. The part is cheaper than paying for a diagnostic fee for a smoke test.

I would tackle it by cleaning or replacing the gas cap and if that doesnt work then replace the vent valve. Lastly if the vent valve didnt fix it id take it in for a smoke test. This order is really just financially speaking cause if those first two options didnt fix it then its something much much more expensive of a fix after that.

 

[Ulitaco]

I purchased the rear valve that goes by canister. I am going to try to get to it this week. I will get back to u. Does anyone know how to clear a permanent code?

What do you mean permanent? Does it not clear with an obd2 scanner?

 

[Ulitaco]

Interesting. Definetly would be great if that works. Saves alot of labor time for sure.

 

[Ulitaco]

P0456 is back! So, that's fun.

Christ…what where you doing at the time it popped back up? Like driving on the freeway or parked and idling for example?

During this entire time have you taken it into a shop to have them diagnose at all? Sometimes its cheaper to just pay that fee instead of throwing parts at what we think is the issue.

Also if im not mistaken the vent valve can easily be heard actuating just with your drivers window down while parked and idling. I havent really timed it but its definetly actuating every like 15-30 seconds or so. Thats one way to check its activating.

 

[Ulitaco]

They only diagnose. They have to get permission from you to move on any further than just diagnosis usually with a phone call.

 

[Ulitaco]

This code just showed up on the wife's 11' Pathfinder. I hope it doesn't get too complicated.

Try the easy fixes first. Check gas cap,change gas cap, change vent valve and change evap canister. Id say its cheapest in that order. None of these work then id take it to the shop for a smoke test and further diagnosis.

I dont know about other Xterras but my 2015 pro-4x actually has a message in the odometer area that says to check gas cap so it kind of gave me the idea to rule that out as the problem for my P0456 code. The fix for mine was a new vent valve