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Help with evap leak

DylanM345

Bent currie club
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Joined
Jul 18, 2019
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1,727
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San Francisco, CA
Have had an evap leak for a long time now. Am going to get it smoke tested soon. Getting the codes P0442 and P0456. Already replaced the gas cap, my MPG is down in the shitter lately too. Used to get 14.2 pretty consistently, am now averaging 11-13. Ive checked the hoses on the evap canister, all seem to be in good shape, any spots that people know of are the "go-to" for the line splitting/ casuing the leak? And would this be the reason for my bad MPG?
 

LittleTankTJ

TJ Euthanist
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Joined
May 9, 2019
Messages
526
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Bay Area, CA
I was chasing something similar for a long time. I had a bunch of work done, evap canister and new fuel tank, and it stopped happening.

Do you get a fuel smell when you fill up your tank?
 
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someguysjeep

simple guy
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Nov 17, 2019
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ohio
i had a leak in the braided line from the fuel rail to the hard line on the frame, took sometime to find because the leak was hidden by the weave and that trapped it from showing a witness.
 
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OP
DylanM345

DylanM345

Bent currie club
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Joined
Jul 18, 2019
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1,727
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San Francisco, CA
I was chasing something similar for a long time. I had a bunch of work done, evap canister and new fuel tank, and it stopped happening.

Do you get a fuel smell when you fill up your tank?

Not that ive noticed, no. Ill keep that in mind when I fill up next.
i had a leak in the braided line from the fuel rail to the hard line on the frame, took sometime to find because the leak was hidden by the weave and that trapped it from showing a witness.

Was fuel leaking out of it? How did you end up finding it. Ill take a peek today.
Make sure the purge valve is sealing, they can create a internal vacuum leak thus poor mileage and performance

Thanks for this, where does one find the purge valve?
 

Moglocker

TJ Addict
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Joined
Mar 19, 2021
Messages
1,325
Location
Missouri
Not that ive noticed, no. Ill keep that in mind when I fill up next.


Was fuel leaking out of it? How did you end up finding it. Ill take a peek today.


Thanks for this, where does one find the purge valve?

Have you had the fuel pump out lately?
 
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someguysjeep

simple guy
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Nov 17, 2019
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5,002
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ohio
Was fuel leaking out of it? How did you end up finding it. Ill take a peek today.

no. not a drip but when i was under the jeep and close to that line i could smell it, and ran my hand along it and it got damp with fuel. that braided section if you have it is the only real hiding spot, most everything else is visible down the frame rail until it goes over the tank. the other tube that travels next to it should go right to that purge valve on the fender out in front of the brake booster, IIRC.
 
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bobthetj03

WRKJ779, KN6SRH
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Feb 3, 2017
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14,664
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Clearlake Ca.
The hard lines leading from the tank along the frame and up to the intake manifold have rubber hose right as the lines go up the firewall. Check them where they clamp to the hard lines. Also check the 90* rubber boots that plug into the intake.
 
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Moglocker

TJ Addict
Supporting Member
Joined
Mar 19, 2021
Messages
1,325
Location
Missouri
That was my evap leak, I didn't tighten that damn ring enough. What a pain in the ass that was. Hopefully @Moglocker didn't get that one right, dropping the tank sucks.

I had the hatch,it took 5 minutes,the smoke was puffing out 😂

FC6F9C5C-B2E6-466D-A53B-059E1A62337A.jpeg
 
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