You'll get a code or a "gas cap" warning when you take it off, but it'll clear after a few starts once you put it back on. If you replace that white valve, there's a green o-ring on it. Make sure you either get a new one or save the one you have. I spent forever trying to diagnose that stupid gas cap warning message after I replaced my canister and it was because I was missing a 75 cent o-ring. Put it on the parking lot at the dealership and the gas cap warning immediately went away.

Oh, and neither the canister or the white valve attached to it made a rattling noise that I remember.

 

Gonna give it a shot...thanks man!

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I thought i could hear mine once and then figured out that it was a loose drivers side rear control arm bolt.

 

Yeah I went under and fully checked torque on every bolt in the suspension. Driving me nuts

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I've got the same issue, a rattle coming from the back when I go over a bump. Everything else is tight but when I hit the canister with hand it rattles.

Did replacing the canister help you guys? I'm lost and it's driving me nuts.


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I just replaced the white end piece ( ESIM module) and the brand new one makes the same rattle.

The big black canister itself makes no noises when I tap it.

Looking inside the old white module theres a little cylinder that slides back and forth in a channel that causes the rattle.
Unavoidable as it seems.

Stupid design #100 for Chrysler....lol

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I know this is a really old post, but I'm getting this rattle now too. Crawled under to investigate (hit shit) and yuppers. Hitting the evap makes the rattle! Did replacing "the white part" fix it. Or whole canister needed.

 

Nope...that rattle is by design. I've crawled under a few jeeps still in the lot and they all did the exact same thing.
It has to be there since that little white rattling bastard has to move back and forth in the slot.

I finally tracked my rattle noise to the rear calipers.

When I hit them they'd sort of clunk/rattle.

It was the slide pins. They were bone dry and out of grease for some reason.

Took it apart and crammed them full of caliper grease and now it's completely silent.

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