Chances are the charcoal canister has fuel in it which increases the amount of fumes in the filler hose. This happens when people 'top off' the tank after the nozzle has clicked off. You should stop pumping when it clicks off. Continuing to fill the tank overfills it and the fuel drains into the canister.

Sounds to me like a common problem... Fuel tank vent valve, as they get older the solenoid is/becomes weaker and is unable to open fully. Thus creating a restriction, over time it gets worse and worse until it fails and a check engine light.

If I'm not mistaken, the vapor canister is under the hood, not by the fuel tank. I saw a youtube vid where it's replaced unless there is a cylinder type of component. Does anyone know the AC delco or substitute part number for the canister near the gas tank?

Dorman® - Chevy Monte Carlo 2000-2001 Vapor Canister Components

Since it's a problem during refueling, I would think it's more than likely a problem with the early fuel evap system which is located under the car near the gas tank. (15) evap canister in the diagram below. Verify the part # at a Chevrolet dealership because they will be able to pull up what you need.

http://www.tonkinonlineparts.com/ima...091W03-041.JPG

When I top off my tank this must have filled up with gas AC Delco 214-2147. According to my service manual, in order to change the canister I have to drop the gas tank cause it's on top of the gas tank.

I could be mistaken...
But I do believe on your Model year there is a trap door to access the fuel pump/lines etc under the Mat.. Thus allowing you access it from above without having to drop the fuel tank.. Its quite possible you may also be able to reach/replace it thru this opening.

In my avatar the bottom right pic is in my trunk. To access the canister from inside the vehicle I would have to remove all those batteries and steel rod frame battery tray bolted to the car. ughh maybe I'll just fill my tank slowly.

Solved!
 

Same problem with my 2002 SS. Especially if it's warm outside. I've never had this kind of thing happen on any car I've driven in 30+ years. I pumped gas for a job for 6 months once too(all spring and all summer, VERY busy station on I-5 in OR). Never ran into it there either(NO BS!). So all this talk like it's a "common" problem is "bogus"...IMO. Unless by "common" we're talking with whatever GM rigs have this stupid issue for whatever reason. Which might be VERY "common" for all I know(my 98 Monte didn't have it). Doesn't seem "uncommon". That's for sure(umpteen threads on the ol' interwebs).

Anyhow...I ain't puttin' up with it. It's getting fixed one way or another. However I have to rig it. Just got the bright idea to open up the EVAP service port while filling up. It's just a Schrader valve. Get a Schrader valve core tool. Remove the core. Fill tank. Install the core. See gas gauge > ¾ (which is about as full as mine gets without a fight).

:Head Banger:

NOTE: Not that it's legal to do that kind of thing. It's just an idea...wink...wink...;)

UPDATE 6/28/20: Sooo...I tried that. Sort of. By that I mean I opened the valve without removing it while filling up. It did work, but it didn't work. By that I mean I can hear vapor hissing out of the valve will it's filling. But it didn't make any difference with the gas pump wanting to kick off prematurely. Which means...IT PROBABLY DOESN'T HAVE ANYTHING TO DO THE EVAP SYSTEM!!! It's most likely just some kind of restriction in the filler tube assembly. Which is...WTF ever. All I know is...I can't pump my own gas where I live...and it's gotten so bad it'll only fill ~$1 or so at a time before it kicks off for no reason. And the pump jockeys just aren't equipped to deal with that crap. So...parts cannon loading....

UPDATE 7/3/20: I think I might have discovered the ultimate workaround. I still need to try it a few more times to confirm. But if it turns out I'm right...it's a very simple fix that doesn't require replacing anything or doing anything complicated at all. I shall return...:)

UPDATE 7/11/20: SOLVED! I was right!

Engine OFF > Ignition switch ON > Fuel

Works every time. Went from damn near impossible to no problem whatsoever. Just like that! :happyanim:I haven't figured out why having the ignition switch ON fixes the issue. Something(s) obviously gets turned on that does whatever it does to make it work correctly. Probably the fuel pump and/or some other EVAP thing. I'll let you know if/when I bother to figure it out...