2002 Ford F150 Truck missing out between 1500-1900 RPM's

I have had this bad running (missing) condition happen to me on both my Suburban and now my F-150 (1400 to 1600 RPM). I will bet you have used some type of spark plug other than what you had in there previously (or not factory recommended). This appears to be a problem with these new high energy EFI ignitions. I have not investigated all of hte reasons behind the reason, but I have come tothe conclusion that something in the programming of how these systems set up their firing enregy and changing that spark energy for various conditions is the root of the problem. So the cure is YOU MUST REPLACE WITH THE EXACT SAME TYPE (in my case Motorcraft) and number (AGSF34FM Platinum) to get the expected performance from your particular engine (mine 4.2L 6-cyl). (I tried Autolight plugs. NO GOOD! Even though platinum.) As for the codes, I think that should fix the P0171 & P0174.
The P0131 & P0151 codes could be that you have a seal leak at the sensors or the air filter inlet area. (This was given to me by a very good mechanic.) Mine produces the same codes, but only when it was a cool night (not REAL COLD) and I start it up in the early morning. This mechanic claims that briefly the cool air is coming into the air filter chamber at the wrong point across these sensors and causing an un acceptable error condition in the computer, which is why it only happens during this time. I have not checked my seals or gaskets yet, so I do not know if this is the real solution.