Evap purge system small leak

Baker

New member
So guys i need a little help. When i came out from work today on this hot summer day i went to start the jeep and got a check engine light. I checked the code and it was p0456 which is evap purge system small leak. Had anyone had this before and what did they do to fix it. Thanks guys.
 

wayoflife

Administrator
Staff member
The gas cap is what your dealership will check first but, from what I've seen, you most likely have a leak where the small white box that is attached to the larger black canister.
 

TheDuff

New member
I had that code for 2 yrs. Wasn't the gas cap. I knew it was a real small leak because I could sometimes go for 3 or 4 hundred miles before the code came back after I cleared it. This year I was getting worried since I had smog coming up, but in April I took the family camping, it was pretty muddy and after the trip the code didn't come back. I smogged the jeep 2 months early out of fear of that code. So far, it still hasn't come back up. Mud ftw and if it does return I'll just replace that over priced evap canister
 

nmwranglerx

Caught the Bug
The gas cap is what your dealership will check first but, from what I've seen, you most likely have a leak where the small white box that is attached to the larger black canister.

Yep. This is exactly where my leak was. It's an inexpensive part under $20 I think. If the gas cap doesn't fix the issue I would replace this. It will be a lot cheaper than smoke test
 

wayoflife

Administrator
Staff member
Yep. This is exactly where my leak was. It's an inexpensive part under $20 I think. If the gas cap doesn't fix the issue I would replace this. It will be a lot cheaper than smoke test

Yeah, had the same problem here on more than one occasion. I didn't even know you could buy the part separately - I just used a little RTV to make a gasket and it did the trick for me.
 

Baker

New member
Ok thank you all so much i will check all of these things out here soon and let you all know. Thank you all very much.
 

Baker

New member
Ok i checked the gas cap and it was on tight and everything, i got under and i didnt fiscally see any leaks on the small white box to the black canister but that doesn't mean theres no leak. Which part are you guys actually changing out? Also if its still under warranty wont the dealership fix it for free. As long as i didnt void it with any thing i have did so far.
 

nmwranglerx

Caught the Bug
I don't think you'd be able to "see" a leak of this type. The little white box is called something like the detector. It's item number 2 from this graphic. If you are under warranty it'd probably be worth having the dealership fix it. Also, you should know that the code will stay up for a while even if you fix the leak. The system has to cycle through a bunch of different sensors before it eventually goes out. To speed this process up you can disconnect your battery cable for 30 seconds and then reconnect. This will reset the system. If you still have the leak, the code and indicator will come back on again.

Screen Shot 2015-06-18 at 9.36.51 PM.png
 
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Baker

New member
I don't think you'd be able to "see" a leak of this type. The little white box is called something like the detector. It's item number 2 from this graphic. If you are under warranty it'd probably be worth having the dealership fix it. Also, you should know that the code will stay up for a while even if you fix the leak. The system has to cycle through a bunch of different sensors before it eventually goes out. To speed this process up you can disconnect your battery cable for 30 seconds and then reconnect. This will reset the system. If you still have the leak, the code and indicator will come back on again.

<img src="http://wayalife.com/attachment.php?attachmentid=149544"/>

Thanks i will disconnect battery cable after work today and if its still there, i will take it to the dealer. Thanks alot guys for the help.
 

Baker

New member
Hey thanks guys, i diconnected battery cable and the check engine light went away. Thanks again.
 

zx6r

New member
i have had the same code for a few weeks now. it came on a few weeks after i relocated the evap canister. i have cleared it twice using my procal but it keeps coming back a few days later.
 

Baker

New member
i have had the same code for a few weeks now. it came on a few weeks after i relocated the evap canister. i have cleared it twice using my procal but it keeps coming back a few days later.

I just disconnected battery cable and it hasn't come back since, you may actually have a small leak somewhere. Try taking a look at the part mentioned from the other guys and see if that helps.
 

RTillery

New member
I relocated my canister using the Nemesis kit. I got the gas cap notice a few days later. Cleared the code and it came back shortly. I read that when you relocate the can, it mounts upside down from the factory location. The cure is to rotate the white box in it's mount on the canister 180 degrees back to it's original orientation. I was miffed that this wasn't in the directions and I had to pull the whole mess back out to access the little tab that keeps it in place. It was a pain in the butt and would have taken like 10 seconds to do if it were in the instructions.

If you have relocated it, the tab is behind the white box and indexes it onto the canister. If you can depress it, the white box will rotate 90 degrees and pop out. Index it around to its original orientation and you should be good. When I did this, the gas cap code showed back up on initial startup, but when I cleared it, it has been perfect now for over a 1000 miles.
 
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nmwranglerx

Caught the Bug
I relocated my canister using the Nemesis kit. I got the gas cap notice a few days later. Cleared the code and it came back shortly. I read that when you relocate the can, it mounts upside down from the factory location. The cure is to rotate the white box in it's mount on the canister 180 degrees back to it's original orientation. I was miffed that this wasn't in the directions and I had to pull the whole mess back out to access the little tab that keeps it in place. It was a pain in the butt and would have taken like 10 seconds to do if it were in the instructions.

If you have relocated it, the tab is behind the white box and indexes it onto the canister. If you can depress it, the white box will rotate 90 degrees and pop out. Index it around to its original orientation and you should be good. When I did this, the gas cap code showed back up, but when I cleared it, it has been perfect now for over a 1000 miles.

Sounds like a good tip for those who have relocated with the kit you're using
 

srosario

New member
im still getting the codes p0455,p0456,p0457
i replaced the gas cap and the small white box, with oem.
any ideas?
 

Owl

New member
I had the same problem(s) for months. Checked all of the fittings, canister, valves etc. Replaced the cap. Then I started tracing the tubing from the canister, forward to the engine. Found a broken fitting on the rear of the gas tank (sorry, the pictures aren't great):

IMG_0950.JPG

I found some stainless steel tubing ~0.180" OD. Had to drill out the inside of the broken fitting (and the fitting at the gas tank). The fitting on the tank doesn't appear to be replaceable, and a new tank is over $600.

IMG_0956.JPG

Mixed up some epoxy glue, and applied liberally (careful not to get glue into the interior of the stainless steel tubing).

IMG_0957.JPG

So far, so good. No idea how / why the fitting broke, but have subsequently found that the problem is not uncommon. Hope this helps for any future busted knuckles.
 
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