The tube we are talking about is the one on the right near the fuel fill tube. You can see where there used to be a zip tie that I clipped off.
This is where the tube enters the fender well splash guard at the top. After you remove the zip ties that hold the three tubes together this will pull right out at the elbow.
This is what it looks like after you pull it out. Mine was much dirtier but I cleaned it off as I was going to be putting my mouth on it. After cleaning, make sure the gas cap is removed and simply blow into the tube if you can blow through the tube and you hear air going into the gas tank, this would probably not be your problem. When I blew into mine I could barely get any air through at all. I then sucked on the tube hoping not to get a mouth full of anything and I was rewarded with what I can only explain as a pop like a seal popping. Air then flowed freely back and forth and I could hear the air movement in the gas tank. I had no problem gassing up. BUT.... on the next tank I had the same problem and the first thing I checked at the gas station was this tube and it was plugged up again. I probably looked funny sucking on the tube at the pump but it only took a second and it was clear and fueled fine. I just gassed up yesterday and it filled perfectly and I didn't have to unclog the tube this time. I have left the zip strips off in case I have to do it again in the near future but so far it looks good.
An easy fix to a frustrating problem. I hope this helps you.