Krumby

2011 jeep wrangler unlimited malfunction light came on and I got the code which was P0456 looked it up and it says its a Evap purge system small leak anybody know what that is ? How do I fix it ?
Thanks
Dave

Mark Doiron

I've been nursing mine for about twelve months now. I clear it and it stays gone month or two, then comes back. Some folks have replaced the gas cap to clear.

rob_engineer

I got an error in my 2012 that actually said "gas cap". Well, it wasn't the gas cap. I just tweaked the hose side to side that goes into the evap canister and the light instantly went out. That was almost a year ago. It's never come back on. The hose must have been not sealed well and was letting a tiny bit of air in.

Sierra141

Mine turned out to be the aftermarket locking gas cap. Went back to the stick one and is gone.

101gargoyles

Cleaned gas cap tube neck and rotated the cap O-ring. Still have code. Which hose are you mentioning? Does it follow the fill tube down toward evap canister?

rob_engineer

the hose I tweaked was inside the engine compartment. Drivers side close to firewall. I think the hose that went into the canister was maybe 5/8" diameter. It was over a year ago so I am not positive. Give me a couple hours and I can post a picture of it

101gargoyles

That would be helpful because another thread talked about a hose under the hood that I couldn't find on my 07 by the description.

Mark Doiron

Mine got fixed once I put a little Vaseline on the O-ring. Just a tiny bit.

rob_engineer

here are the pics, but keep in mind this is a 2012. The hose I manipulated by twisting a bit is the one that goes into the evap canister.

101gargoyles

Took that info out to mine that was showing only a P0456 code and equipped with the stock locking gas cap.
Noticed filler neck surface that mates to the cap O-ring was sort of nicked/scratched a bit and had some type of oily film/dirt on it. So went back out with some Scotch Brite pad and cleaned that all up. Then I removed the cap O-ring and rolled it over to use the opposite face. Used a Q-Tip to lightly apply the Vaseline and closed her up. No I didn't try to clear the code manually I just figured if it's cured the CEL will disappear after enough run cycles. NOT
Well after a few weeks I took her in to my mechanic for an oil change and asked him to check out system for any other source of the code. He only found a different code that was the one for a bad rear oxygen sensor-I think he said P1*** something. Replaced sensor and now no codes at all.
Wondering now if the cap work I did fixed the original code and just by coincidence that second code popped up in the month or so from the time I got the original code to when I finally got around to doing the cap cleanup.