Hyundai Repair: Fuel Tank Question, hundayi sonata, charcoal canister

Question
I have a Hundayi Sonata 2001.  Recently I have noticed when I try to fill up with gas, regardless of the gas station, it is hard to fill up the tank without the gas pump doing the automatic shut off unless I hold the gas pump handle and nurse it at a very slow fill speed.  This seems very unusual to me and only recently started happening.  I am wondering if there might be some connection to this problem with something in my fuel tank.  As I mentioned, up until recently I never had trouble like this.  I could set the gas pump handle to fill with the catch lever to keep it going and I didn't have to hold it or nurse it to fill up until right at the very end.  Now I have to continuously hold the handle and can only fill it up at a very slow speed.  Thanks for any thoughts on this.

Answer
In most cases, this is caused by a restriction in the fuel tank vent system, either in the charcoal canister or the canister filter.  I've also seen a few instances when the purge control valve is stuck shut.

Another potential but less frequent issue is that there is some sort of blockage preventing the fuel from entering the tank.

Most likely, you'll need to take the car to a good driveability mechanic/shop to determine where the problem lies.  Many mechanics have difficulty diagnosing this sort of issue because of the many areas where the problem may lie.