Code p0456 Evap small leak

SD38-2 · Aug 10, 2017

My 2014 1500 threw a CEL when I started it to leave work yesterday. I took it to a parts store so the can see what code caused the light. The guy showed me I had one code and it is p0456 for a small leak in the evap system. He said it could be a loose gas cap to a leaky hose or other things. How long is the warranty on these parts? my truck is at 42,000 miles now. Is this something I can self diane or would I be better off taking it to a dealer or a local shop? I'm very mechanical but my previous truck for over 10 yrs was a 2nd gen cummins so I'm not to sure of the emissions equipment on a gas powered truck. I did remove the gas cap and retightened it, I'll give a few days to see if the light goes off.

WilliamS · Aug 10, 2017

Could be super easy like the fuel cap, or something hidden under the bed of the truck. If you are lucky it could be the fuel cap o-ring. inspect it to see if its bad, if its not it can be a real pain to track down the leak.

deangtp · Aug 10, 2017

I had a persistent crap leak and tried a gas cap from a parts store. It didn't fix it. I goofed with some other things and made sure things were right. Ended up buying a gas cap from the stealership, and the light went away. I probably driove 20k miles with it on.

Tach_tech · Aug 10, 2017

I've seen a fair bit of purge valves causing the P0456 to set. They changed to a different style and some seem to leak. There's also been a PCM update to address a small evap leak as well. Best bet is trying the dealer if you can. Or you can just clear the code and wait a couple weeks and see if it comes back.

West27 · Aug 10, 2017

My truck did the same thing and it turned out to be a bad PCM and it kept resetting itself so they had to replace it under warranty and it has been good ever since.

RamCares · Aug 11, 2017

SD38-2 said:
My 2014 1500 threw a CEL when I started it to leave work yesterday. I took it to a parts store so the can see what code caused the light. The guy showed me I had one code and it is p0456 for a small leak in the evap system. He said it could be a loose gas cap to a leaky hose or other things. How long is the warranty on these parts? my truck is at 42,000 miles now. Is this something I can self diane or would I be better off taking it to a dealer or a local shop? I'm very mechanical but my previous truck for over 10 yrs was a 2nd gen cummins so I'm not to sure of the emissions equipment on a gas powered truck. I did remove the gas cap and retightened it, I'll give a few days to see if the light goes off.

Hi SD38-2,

If you end up deciding to visit your local dealership for further diagnosis I'd be happy to offer assistance if needed. Just PM our page with your VIN and let me know!

Andrea
Ram Social Care Specialist

SD38-2 · Aug 11, 2017

WilliamS said:
Could be super easy like the fuel cap, or something hidden under the bed of the truck. If you are lucky it could be the fuel cap o-ring. inspect it to see if its bad, if its not it can be a real pain to track down the leak.

I tighten the cap the other day but I'll check it tonight and see if the o ring is damaged.

Tach_tech said:
I've seen a fair bit of purge valves causing the P0456 to set. They changed to a different style and some seem to leak. There's also been a PCM update to address a small evap leak as well. Best bet is trying the dealer if you can. Or you can just clear the code and wait a couple weeks and see if it comes back.

Is there anyway I can check or test the purge valve myself or does a smoke test have to be done to check it?

West27 said:
My truck did the same thing and it turned out to be a bad PCM and it kept resetting itself so they had to replace it under warranty and it has been good ever since.

At what mileage did your pcm go bad? I'm at 42k so I'm past the 3/36 bumper to bumper but I still have powertrain warranty on my truck.

ramcares said:
Hi SD38-2,

If you end up deciding to visit your local dealership for further diagnosis I'd be happy to offer assistance if needed. Just PM our page with your VIN and let me know!

Andrea
Ram Social Care Specialist

Thanks Andrea, if it doesn't clear up on its own I'll probably take it to my local dealer.

deangtp said:
I had a persistent crap leak and tried a gas cap from a parts store. It didn't fix it. I goofed with some other things and made sure things were right. Ended up buying a gas cap from the stealership, and the light went away. I probably driove 20k miles with it on.

If it doesn't go away on its own I might try a new cap from the dealer, if that doesn't work I'll take it in. It doesn't effect drivability but next year I'll have to smog test my truck when I go to renew my plates.

West27 · Aug 12, 2017

Mine went bad before 20k but I would think that would fall under the powertrain warranty.

SD38-2 · Aug 12, 2017

I went to get my truck filled up at my local shell this morning. I left my house and my CEL was still on. I fill the truck up and leave the station and now the light is out. I checked the gas cap o ring and it looked good. Hopefully it stays off and it was just a loose cap.

Tach_tech · Aug 12, 2017

The best way to test the purge valve is a smoke test.

SD38-2 · Aug 16, 2017

After a few days the engine light came back on today for the same code as before. It came on when I started my truck up to leave work. I'll make an appointment with the dealer soon before my wife and I leave on a trip to NY and Canada in a few weeks, we are taking the truck.

5hole · Aug 17, 2017

I had the same issue twice. Turned out a squirrel ate through a line under the truck. Dealer found it after a smoke test.

PostalTwo · Oct 25, 2018

I just fixed a p0456 on my truck last weekend . Used a scan tool and some pinch pliers and diagnosed it in less than 5min. Purge valve was leaking. Removed the valve,confirmed it failed and replaced.

Lance E · Jul 26, 2019

2016 ram, same problem, dealership has replaced gas cap twice, replaced the ESIM twice, and replaced the sensor. Light has come back on and now they are telling me that RAM has discovered its a software problem in the computer and they don't have a solution yet. Not sure what to do now. They are telling me to bring it back in, but if they don't have a solution, what is the point?

Bigskyroadglide · Jul 26, 2019

Top of the gas tank. 5 minute job. $16 dollar part.

Code p0456 Evap small leak

SD38-2

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WilliamS

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deangtp

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Tach_tech

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West27

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RamCares

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SD38-2

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West27

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Tach_tech

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