x2 on fuel pressure gauge. and the electric fuel pump is cooled by the fuel in the tank so always keep over 1/8-1/4 of a tank of fuel in the tank. the extra fuel filters are for older vehicles that may of built up residues in the fuel system. after a filter change or two the system should be o.k. the oil pressure fuel pressure boost system is what i was talking about. not the tank pump...ford has had issues with it, thus the 6.7 changes resolving the issue... only complaint i have with the newer trucks. you have to lift the cab out of the way to service the valves/head.