If it were my truck, I'd just drive it for 6 months or more to make sure it was reliable before attempting any upgrades. Make sure all fluids have been changed, filters, etc.
I can't see or test your truck from here, unless you are in Phoenix. The best I can do is to provide information.
Do you live where they salt the roads? If so, probably rust and corrosion is a big part of your problem
You meant FPR (fuel pressure regulator), right? Or did you mean FPRS Fuel rail pressure sensor? It's difficult to keep all those abbrs straight and everyone on the same page.