Ask The Expert- Troubleshooting P0457 after EVAP relocation

#1
What recommendations does everyone have for troubleshooting an evap leak?

After relocating the EVAP canister with the MetalCloak bracket, I immediately got the gas cap warning. A couple of trips later, it turned into a P0457 check engine light (EVAP system leak detected).

I checked that I'd tightened everything, cleared the codes, but got the gas cap warning again as soon as the key was in.
I took everything off and put it back together again, with a helping of silicone grease for the o-ring on the vapor leak detection pump. I tightened everything up again, cleared the codes, but again got the gas cap warning, which turns into a P0457.

Before I buy or build a smoke test apparatus, are there other things I should check? Should I worry about the slight kinks in the bottom left evap hose? I was inadvertently rough with the leak detection pump to clock it for installation, and it looks like the silicone grease has come out from that o-ring connection. Should I duct tape it up to see if that's my leak? I've also got my eye on the connection from the hard tube coming from the fuel filler, where it connects to the rubber hose to the evap.

Which steps would you take next?

IMG-6278.JPG
IMG-6280.JPG
 

Pthorpe84

Moderator
Staff member
#2
I have really struggled with this myself. Mine has shown that code for over a year and I have done everything but replace the damn thing. I can get the code to go away for about a day or so by adjusting the angle of the large connection with the hose and connector feeding into it. If you fine a fix, I would love to hear it.

And yes I did check my gas cap too lol
 

TJDon

Wrench guy
#3
That white colored box there in the canister is the EISM. There is a spring valve in it that causes a lot of leak codes. I’ve replaced dozens of them. But also make for certain that the canister is being mounted in the exact “as it was” position before you moved it. Gravity will screw it up and cause a light to come on
 

Pthorpe84

Moderator
Staff member
#4
That white colored box there in the canister is the EISM. There is a spring valve in it that causes a lot of leak codes. I’ve replaced dozens of them. But also make for certain that the canister is being mounted in the exact “as it was” position before you moved it. Gravity will screw it up and cause a light to come on
That makes some sense. I know mine is not sitting exactly level.

Can the spring valve be cleaned if it’s just getting hung up?
 
#7
Update: I'm cautiously optimistic that I solved my issue with just a simple battery disconnect.

I disconnected the battery for a few days over the Thanksgiving weekend to strip, prep, and coat bedliner in the tub of the JK. When I put it all back together and took it out for a test drive, the Jeep didn't complain about the gas cap immediately on startup. I've taken it on a couple of around-the-block trips without it popping up, so I'm hopeful the check engine light is behind me. If the battery disconnect was i the answer though, what a stubborn code it was to not even flinch when cleared with the programmer tool.
 
Top