P0449 still persists after changing out charcoal canister and both valves?

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ClassFAirspace

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2018 Escalade ESV with 131,000 miles

I got P0449 a week ago and finally got all of the parts together to change out the related components. I used all ACDelco components to change out the charcoal vapor canister (84106549), vent valve at the back (84148820) and purge valve on the engine (12630282).

I cleared the code and then it immediately came right back the next time I started it up. My code reader says one of the instances of P0449 is "permanent" and I will need to drive 200+ miles without malfunction until it clears. Could this be why the check engine light and code keeps popping back up or is it going to be a wiring issue now? Also, if it is the wiring issue how big of a pain in the butt is it going to be to replace?
 

West 1

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Does your scan tool allow you to test the EVAP system?

If it is working properly driving can get you cleared again. I have only worked with one Permanant code and that was on a Mercedes, same thing, had to drive the miles and have a number of trouble free starts before it would clear.

On EVAP issues I have found a smoke machine to be very effective finding the problems before installing new parts. Of course it does not find electrical issues only failed lines and canisters.
 

Fless

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Joseph Garcia

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Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.
 
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ClassFAirspace

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Does your scan tool allow you to test the EVAP system?

If it is working properly driving can get you cleared again. I have only worked with one Permanant code and that was on a Mercedes, same thing, had to drive the miles and have a number of trouble free starts before it would clear.

On EVAP issues I have found a smoke machine to be very effective finding the problems before installing new parts. Of course it does not find electrical issues only failed lines and canisters.
I do believe it does.

I will have to test it again tonight when I get back home after work, if not looks I will be crawling under the car again to trace the wiring and see where it all goes. Rather than trying to find a small break in the wiring, which may not even be visible to the naked eye, I think a more efficient use of my time would be to just replace the entire length.

As for permanent codes, yes it requires quite a bit of time and certain parameters to be met. My understanding is a few of them are 200+ miles without a repeat occurrence, 4 consecutive starts without it popping up, gas tank between 1/4 and 3/4, etc..

I will report back, when I find a fix, as I am all about passing on the knowledge to save the next guy from a headache.
 

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