P0456 & P0457, but I've already changed LDP & PS & gas cap

Curt Gobbell · Jul 7, 2021

I've got a 2014 1500 with 5.7 and 150k miles that threw a p0456 and p0457, but I've already changed the purge solenoid, leak detection pump and gas cap (twice with OEM).

Anyone have a similar/same issue?

Curt Gobbell · Jul 8, 2021

Update #1

Cleared the CELs last night. This am, before cranking the truck, both the gas cap symbol and CEL dash light reappeared.

Its almost as if the truck is doing a pressure test pre-crank, and the test is failing.

John Dahlgren · Dec 1, 2021

I have the same issue and have done the same things with no luck. After I change part and clear codes the gas cap lite comes right back and the P0457 code takes about 30 miles of driving. Not sure where to go from here. If you find a fox please let me know

Rlaf75 · Dec 1, 2021

EVAP codes are very difficult to diagnose and you can waste your money and time replacing all the solenoids, valve and canisters and whatever else you want only to have a pinhole/crack in a line somewhere you can see. A smoke machine is needed to in order to properly diagnose the problem

John Dahlgren · Dec 4, 2021

Thanks. Will take my truck in then. I was able to clear and remain clear now all codes but the P0457. So I am thinking it might be a larger leak.

wallacemf · Dec 5, 2021

On my 2018 2500 6.4, I was getting the P0456 code. Turns out that squirrels were jumping on top of the fuel tank and chewing on the hard plastic (vent?) lines and a section had been chewed out. I spliced in a piece of vacuum line and the code went away.

Hanover Fiste · Dec 5, 2021

I've had code P0456 on my 2005 for the last couple years. I've replaced every component in the EVAP system, except for the hard plastic lines which are no longer available.

When the Check Engine light comes on, I just reset it. Sometimes it reappears the next day; sometimes it takes a few months. The truck runs fine otherwise. I guess I should drop the fuel tank one of these days and take a look there.

Midknight · Dec 5, 2021

I had the P0456 and replaced the same components to no avail. Turns out it appears to be the fuel level sensor. If you're not familiar look it up. If you see you gauge go to empty and then come back you know for sure. My engine light triggers shortly after filling up and again around half tank. Those must be the worn spots. Also, the cold weather does seem to impact this probably from thermal expansion.

John Dahlgren · Dec 8, 2021

Wallacemf, I had smoke test preformed and there was so much smoke coming from above the fuel tank. I appears that I have the same issue. Rodent chewed through two lines and started on the plastic cap as well. Now the hard part is to replace the tank. Mechanic states that these lines are part of the fuel tank and can’t be replaced or spliced due to the size differences. Anyone know about splicing these or where I can get another tank. Also any site I can get parts particular to my vin number. Would hate to order the wrong tank

GTyankee · Dec 8, 2021

If you are going to take the dealers word for it that the lines are part of the gas tank, that is OK by me, but i would first consider taking it to your family mechanic & get their opinion.

Another thing, if you drive longer distances frequently, consider getting the next size larger fuel tank

GTyankee · Dec 8, 2021

Purge valve check

How to troubleshoot EVAP Leaks

This video explains how to find the annoying and often hated small EVAP Leak n Dodge Trucks and Durango.Tho OBD II Trouble code that was set on the vehicle ...

www.youtube.com

smoke test

How to Find EVAP Leaks

How to Find EVAP Leaks with Smoke Pro Diagnostic Leak Detectors

www.youtube.com

wallacemf · Dec 8, 2021

John Dahlgren said:
Wallacemf, I had smoke test preformed and there was so much smoke coming from above the fuel tank. I appears that I have the same issue. Rodent chewed through two lines and started on the plastic cap as well. Now the hard part is to replace the tank. Mechanic states that these lines are part of the fuel tank and can’t be replaced or spliced due to the size differences. Anyone know about splicing these or where I can get another tank. Also any site I can get parts particular to my vin number. Would hate to order the wrong tank

I just went to autozone, they sell bulk rubber vacuum hose in different diameters. I bought a few feet of a couple different sizes, one size fit well. I just cut out the chewed-up section and slipped vacuum line over both ends and clamped it, been fine since.

There’s not a lot of room to work or even see above the tank. I did most of it by feel. I do think Ram sells the line set separately, I remember looking it up on parts sites, if you wanted to go that route. Using vacuum line was just an easier fix.

GTyankee · Dec 9, 2021

I am thinking that Vacuum Line may not last as long as thin wall Fuel Line Hose, or maybe Fuel-resistant neoprene hose

wallacemf · Dec 9, 2021

GTyankee said:
I am thinking that Vacuum Line may not last as long as thin wall Fuel Line Hose, or maybe Fuel-resistant neoprene hose

Yep, I’m calling it vacuum line but it probably isn’t, it’s pretty thick walled hose. I have a piece left, I’ll look at it in the morning and post back.

GTyankee · Dec 9, 2021

It should have print on it, that reads what it is

Every time that i go to an auto parts store they ask what the use for the hose is

wallacemf · Dec 10, 2021

Yep it says ArmorMark windshield washer/vacuum tubing. Pretty thick walls though, it’s working for now.

art94x · Dec 10, 2021

John Dahlgren said:
Wallacemf, I had smoke test preformed and there was so much smoke coming from above the fuel tank. I appears that I have the same issue. Rodent chewed through two lines and started on the plastic cap as well. Now the hard part is to replace the tank. Mechanic states that these lines are part of the fuel tank and can’t be replaced or spliced due to the size differences. Anyone know about splicing these or where I can get another tank. Also any site I can get parts particular to my vin number. Would hate to order the wrong tank

2007 4.7l top of tank roll over valve hose chewed by rodents. able to fix without dropping tank.

wudce · Mar 23, 2023

I had this same problem on my 2013 and like many I change this and change that with no help. I ended up buying a smoke machine and I found my problem which was hole in the valve to canister tube, Mopar part 55398515AB how the tube got a hole rub into I'm not sure but this did fixed my problem.

P0456 & P0457, but I've already changed LDP & PS & gas cap

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