P0456 code, small EVAP leak

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

xumengpeter

Member
Joined
May 13, 2020
Posts
60
Reaction score
20
Location
******* GA
Ram Year
2016
Engine
Pentastar 3.6
So I have had a 2016 ram with the 3.6 v6 for a few months. CEL came on a few weeks ago and I checked with AlfaOBD and it showed P0456, I checked my gas cap and cleared code, was trying to see if it came back. Well it did a few days ago. What is the best way to troubleshoot this? I don`t want to throw parts at it.. Thanks guys.
 

wallacemf

Senior Member
Joined
Sep 3, 2016
Posts
466
Reaction score
503
Ram Year
2018
Engine
2500 4x4 Hemi 6.4
I had the same issue on my 2018 2500 6.4, the same code and eventually the gas cap light came on as well.

I got underneath the truck and started tracing the hard plastic fuel vent lines from the top of the tank. Found that a squirrel or mouse had been chewing the vent line, tore it up pretty good. I cut out the bad section and clamped in a piece of vacuum line, problem solved. ******** chewed through the main propane line on my travel trailer as well- I replaced that and used stainless steel sheathing.

Not sure if your problem is the same but it’s free to check, and if so, a piece of vacuum line is dirt cheap. Auto Zone etc sell it by the foot.
 

huntergreen

Senior Member
Military
Joined
Jan 5, 2011
Posts
12,187
Reaction score
25,933
Ram Year
2016
Engine
hemi 5.7
Often it's the gas cap.
 

bigdodge

Senior Member
Joined
Jan 3, 2014
Posts
523
Reaction score
310
I take the gas cap and apply a small amount of vacuum grease to the seal and it stops the code for me

Sent from my Pixel 4 XL using Tapatalk
 

62Blazer

Senior Member
Joined
Dec 11, 2019
Posts
1,069
Reaction score
1,258
Location
Midwest
Ram Year
2016
Engine
6.4
My '16 2500 6.4 has the same code that pops up about once per tank of fuel (seems to be consistently about 3/4 tank). When I bought the truck the code popped up and found an aftermarket gas cap was installed by the PO, presumably because of the code. Went ahead and bought the correct Mopar gas cap as I didn't like the "feel" of the aftermarket when closing and it didn't have the tether on it. Anyway, code kept popping up. The vapor canister purge valve located on the passenger side upper portion of the engine is common issue. While I hate throwing parts at something without 100% verifying it's bad, at $15 and 5 minutes of work I took my chance and replaced mine but issue is still there. When I get time I'll crawl under the truck and do the proper trouble-shooting.....I carry an OBD tool in the truck anyway so just spend 30 seconds every once in awhile to clear the code, and also know that the code is not causing any issues.
 

jr27236

Senior Member
Joined
Nov 11, 2019
Posts
421
Reaction score
319
Location
New York
Ram Year
2016
Engine
5.7 Hemi
Make a paint can evap smoker and youll find any leak there is. Look it up on YT. I made mine from there and it works awesome.
 

afram1220

Junior Member
Joined
Nov 6, 2018
Posts
8
Reaction score
3
Location
New Jersey
Ram Year
2015
Engine
Hemi 5.7
I had the same issue and it turned out to be the leak detection pump. $20 from autozone on the passenger side frame rail. 10 minutes to swap out.
 

Timsdually

Senior Member
Joined
Jan 8, 2019
Posts
617
Reaction score
405
Location
Jersey
Ram Year
2020
Engine
Cummins
Maybe unrelated, but are you in the habit of "topping off" when you fill up with gas?
Had that happen on my previous truck and wife's previous car and caused the light to come on.
 

nwro

Junior Member
Joined
Jul 26, 2020
Posts
12
Reaction score
8
Location
Florida
Ram Year
2013
Engine
Hemi 5.7
I take the gas cap and apply a small amount of vacuum grease to the seal and it stops the code for me

Sent from my Pixel 4 XL using Tapatalk
This worked for me as well. Took the cap of, cleaned the seal and applied a little grease. Code has cleared and did not come back (yet).
 

AlanWillis

Junior Member
Joined
Apr 22, 2018
Posts
2
Reaction score
0
Location
Owensboro,KY.
Ram Year
2018
Engine
Cummins 6.7
I had the same issue on my 2018 2500 6.4, the same code and eventually the gas cap light came on as well.

I got underneath the truck and started tracing the hard plastic fuel vent lines from the top of the tank. Found that a squirrel or mouse had been chewing the vent line, tore it up pretty good. I cut out the bad section and clamped in a piece of vacuum line, problem solved. ******** chewed through the main propane line on my travel trailer as well- I replaced that and used stainless steel sheathing.

Not sure if your problem is the same but it’s free to check, and if so, a piece of vacuum line is dirt cheap. Auto Zone etc sell it by the foot.
 

ThunderMug95

Senior Member
Supporting Member
Joined
May 3, 2018
Posts
2,189
Reaction score
3,185
Location
North Prince George, VA
Ram Year
2017
Engine
5.7
Dealt with that code for 3 years every 7 days or so…CEL. Just kept clearing it with my scanner. Last month put a new fuel cap and a new purge solenoid. No more lights.
 

GTyankee

Senior Member
Supporting Member
Military
Joined
Nov 2, 2020
Posts
10,064
Reaction score
12,607
Location
El Cajon Calif. 92021
Ram Year
2016
Engine
3.0 ecodiesel
always use the correct Mopar Gas Cap

leak detection pump is located close to the Charcoal Cannister, usually just above it

The Purge Valve on Rams may be almost under the Fuse Box on some older Rams
On newer Rams, it is located under the large hose that runs from the Air Filter Box & the throttle body
If i recall correctly, there is a way to check the Purge Valve, with a strong breath of air, you can YouTube it

I believe that those 3 things are the main cause for your trouble Code

The other reason is usually Rodents
 
Top