I know what it is, and it's an easy fix. All you need is a razor blade or a box cutter. For some reason, the inner lining on the passenger side front tire has a small portion of the lining that extends down, which is not present on the driver-side. I took a razor and cut the excess material off, so it is now like the driver side. No more rubbing since then. Hope that helps.
[SIGPIC]2013 FX4 SCREW 157" wheelbase
LMS 91 Tow Tune
Firestone rear airbags w/in-cab controller
Pro Comp 2" leveling kit