P0456 Code, Small Evap Leak FIXED
JK Jedi
Joined: Apr 2010
Posts: 4,468
Likes: 221
From: SE Michigan
I seem to have gotten my P0456 CEL problem fixed.
Here's what I did.
- Started by 1st checking the purge valve by disconnecting it and trying to blow through it. (everything checked out ok...I couldn't blow through it).
- Then replaced my gas cap (52030387AB), reset the code, ran for 2 days and CEL came back.
- Then I replaced the Fuel Vapor Canister Leak Detection Pump (4861962AB) and its gasket (52129436AA). It's now been 2 weeks and the CEL has not come back on. Cross my fingers, but so far I think that was the fix for me.
So replacing this part and its gasket seems to have worked for me. The most important for me, was that it is now cold in my area and when the CEL is on, your remote start will no longer work and that sucks in my area once you've grown accustomed to using remote start in the winter.
Here's what I did.
- Started by 1st checking the purge valve by disconnecting it and trying to blow through it. (everything checked out ok...I couldn't blow through it).
- Then replaced my gas cap (52030387AB), reset the code, ran for 2 days and CEL came back.
- Then I replaced the Fuel Vapor Canister Leak Detection Pump (4861962AB) and its gasket (52129436AA). It's now been 2 weeks and the CEL has not come back on. Cross my fingers, but so far I think that was the fix for me.
So replacing this part and its gasket seems to have worked for me. The most important for me, was that it is now cold in my area and when the CEL is on, your remote start will no longer work and that sucks in my area once you've grown accustomed to using remote start in the winter.
JK Newbie
Joined: Mar 2020
Posts: 1
Likes: 0
From: egg harbor nj
JK Newbie
Joined: May 2020
Posts: 2
Likes: 0
From: Burnaby, British Columbia Canada
So for the past few months I've been battling the dang check engine light coming on even after a reset. Got the 0456 code and found out that it was the emission/ evap system "small leak." Most folks, including my mechanic suggested starting at the gas cap.
Big surprise, it came back on after a few hundred miles. I checked all of the evap/vacuum lines (or so I thought) and couldn't find the source. I read somewhere that the battery sometimes corrodes a vacuum line which is right next to it. I checked it and sure as hell, small hole from the battery acid or heat. I did a quick cheap and temporary fix in order to diagnose if that was the source of the code popping. I taped the line up with some electrical tape, and 500 miles later, still no codes popping! Thought I'd share this for anyone else who may be dealing with this frustrating code popping and likes to DIY. I'll be replacing the line soon, and figuring out a way to reroute it or shield it from the battery acid.
Once you see where this darn thing is you'll wonder what they were thinking putting it there in the first place. Anyhow, hope this helps someone.
Stay dirty my friends.
Big surprise, it came back on after a few hundred miles. I checked all of the evap/vacuum lines (or so I thought) and couldn't find the source. I read somewhere that the battery sometimes corrodes a vacuum line which is right next to it. I checked it and sure as hell, small hole from the battery acid or heat. I did a quick cheap and temporary fix in order to diagnose if that was the source of the code popping. I taped the line up with some electrical tape, and 500 miles later, still no codes popping! Thought I'd share this for anyone else who may be dealing with this frustrating code popping and likes to DIY. I'll be replacing the line soon, and figuring out a way to reroute it or shield it from the battery acid.
Once you see where this darn thing is you'll wonder what they were thinking putting it there in the first place. Anyhow, hope this helps someone.
Stay dirty my friends.
[update]
Well, I plugged the hole and the CEL is still off, it had been on for so long that I'm actually starting to miss it.
Last edited by carbo; May 19, 2020 at 10:57 AM.
JK Jedi
Joined: Dec 2010
Posts: 5,642
Likes: 486
From: Knoxville
That's a problem there. You can use some self sealing tape, I think Gorilla makes one. Basically you pull and when you give it a good stretch before sticking it, it activates and makes it super sealed. You could probably get away with cheaper fixes but I would consider the sealing tape to be permanent.
JK Newbie
Joined: Jan 2021
Posts: 9
Likes: 0
From: LITTLE MOUNTAIN
JK Newbie
Joined: Jan 2023
Posts: 1
Likes: 0
From: Salty, UT
I have tried everything in this thread aside from dropping the gas tank and plastic welding the port there. But that doesn’t seem like it would be my problem.
Thanks in advance.
JK Jedi Master
Joined: Mar 2007
Posts: 14,800
Likes: 374
From: Midwest City, OK
