@Rover Range is right - 2 gallons isn't much in a tank that holds something like 22+ gallons.
That said, I did have a failure of my fuel sending unit in late 2013 (which was very early on). For whatever reason, the gauge read more than a 1/4 tank higher than it was...causing a roadside "break down" (in a small blizzard!) on the highway.
In those days, the truck was still under warranty and it wasn't far from the dealer so they came and towed it, diagnosed the problem (couldn't believe it though) and replaced the unit.
I never did find out why but I suspect it had something to do with bad fuel gunking things up (but am not sure).
That said, I don't trust those units much so am replacing my 2013 install (and everything in there) with new components - all from Continental (OEM - I don't want to do this again anytime soon) and sourced by Atlantic British. While working on the truck last month, we lowered the fuel tank and probably screwed up the sender / sensor (again) and now the truck reads empty all the time.
In this case, totally our fault, but it does go to show how touchy those things are.
And, unlike off road diesel trucks, we don't have removable fuel filters / strainers (much to my dismay). The fuel filter is a little plastic sock on the bottom of the sender unit / low pressure fuel pump which sits inside the tank and is integral to the unit (i.e. you can't just clean the thing or even replace it without pulling everything apart).
So that became the reason to just go ahead and replace everything in my fuel tank as part of my major rebuild project.
As
@Rover Range notes, keep tinkering with the fuel and see what happens, let us know!
