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Discussion Starter · #1 ·
Hi all I have a 2016 JKU and I've been getting a check engine light which I've used my superchips to tell me it's P0456 Small Evap leak.

Could anyone help me trace the Evap lines? I've checked the Evap under the Jeep and checked everything out there. The gas cap is fine as well.

Is there anyplace under the hood I should check?
 

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Let the Jeepn Times Roll
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Hi all I have a 2016 JKU and I've been getting a check engine light which I've used my superchips to tell me it's P0456 Small Evap leak.

Could anyone help me trace the Evap lines? I've checked the Evap under the Jeep and checked everything out there. The gas cap is fine as well.

Is there anyplace under the hood I should check?
I've had the same code on another chrysler product. It's a loose gas cap. Not loose enough though to trigger your gas cap warning in your evic.

I know it's weird. I'd take the cap off and reseat it and give it a couple of good turns. Reset light and see if it comes back
 

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.Odds are it could be the gas cap as rubiman said. Clean the gasket and the fill neck where the cap makes the seal. Put the cap back on and turn it until it clicks at least 3 times. If that doesn't work you'll have to do a visual inspection of the EVAP system and possibly smoke test it if you can't see anything wrong.

It's a 2016 so I'd probably go back to the dealer if the above doesn't work and let them smoke test it if needed. That's what the warranty is for.
 

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Discussion Starter · #4 ·
I'll try the gas cap again and see if that's the issue.

I just wasn't sure if there was another place to look.
 

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I had that code along with several others off and on for over two years with my Sebring. They replaced many parts, smoke test, various diagnostics, etc. The faults would pop back up after a few weeks or months.

One reoccurring problem was a bad ESIM (EVAP System Integrity Monitor) switch. After the third replacement I told the service adviser that I could not possibly be having THAT much bad luck with defective ESIM switches. He turned the matter over to his top "old fart" electrical guru technician, who traced the problem down to moisture in the filter that feeds the ESIM switch. He replaced it, along with a new ESIM switch, and the problem has not returned.
 

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I've had the code a couple of times on my '07 JKU. The first time, I did the same as you and checked all the lines on the fuel filler and evap canister and I replaced the gas cap. Nothing worked and then I read somewhere that there is a fuel vapor return line that runs very close to the battery. At least on the early JKs it would tend to rub on the battery compartment and make a hole in the line. I found the hose and sure enough, there was a hole. I patched it up and the code cleared up in a day or two.
Another time I got the code and it was because I didn't tighten my gas cap. I tightened it up and it cleared up in a couple of days.
If you don't feel like waiting a days for the code to clear, you can disconnect your battery. I think you have to leave it disconnected for at least 8 hours ( someone may correct me) for the code to clear.
 

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It's your esim next to your fuel tank .. Replace it and the filter .. Odds are your filter is full and letting dirt into your esim causing it to lose seal
 

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It's your esim next to your fuel tank .. Replace it and the filter .. Odds are your filter is full and letting dirt into your esim causing it to lose seal
A bad ESIM switch filter is what kept causing my switch to fail. Fortunately, the dealer has a fixed for life guarantee so I only had to pay for the first of three switches and labor.
 
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