I have a 2012 Chevy Suburban 1500 with 173,000 miles. Several months ago I started having issues where the pump would stop while filling up. Eventually I got a check engine light that gave the code P0455 (Large Evap Leak). 

I dropped the tank and blew all the lines out (found charcoal bits in multiple areas; tank, fuel pump, lines, etc.), while tank was dropped I replaced the Canister as the charcoal had broken apart, the cylinder and the evap valve under the hood. The issue did not resolve itself, I purchased a used tank that I was just finally able to replace as Chevy dealership said there is a valve INSIDE the tank that can get clogged and that was likely the issue since I had already replaced the Canister, Cylinder and Evap Purge Valve and gas cap.

The lines have been blown out at least 3 times now, closer to 5 times, no new charcoal found in any of the lines when doing follow up work, fuel pump is already brand new. Installing the newer "used" tank did not resolve or make the filling issue any better.

Looking for some ideas on what else could be causing the vehicle to stop so many times while fueling up. If I set the pump to the higher setting it will stop around every 1-4 gallons, if I set the pump to the slower setting I can get anywhere from 6-12 gallons before it stops. If I remove the pump and let it "breath" for a minute, then it can fuel longer before stopping again. I have done everything I have read/been told about to fix this engine code, any additional help would be amazing.