2003 F150 4.6 P0172 & P0174 at same time

89k miles. Idles in park very smooth. Put in gear and can't run more than 30 mph(stumbles, misfires,
pre-ignition, valve noise) Had ford diag and they say coil pk 5,7,8, new plugs, maf, comp. reprogrammed. I take it, change 5,7,8 coil pks, new plugs, clean maf - {No change} I take it to another ford dealer and they say change coil pk 1, new plugs, maf, but the comp does not need to be reprogrammed. So I take it and change 1,2,3,4,6 coil paks, check the new plugs i already had,
put new ford maf - {no change}
In this forum i noticed a lot of things like fuel pressure,catalytic converters, o2 sensors, intake gaskets but ford makes no mention of these in their diag. At the prices they charge shouldn't one expect to hear about these items and if they could be part of the problem.

So what are really trying to ask? whether you were ripped off or whether the forums are incorrect and the 2 dealers aren't? We can't judge how accurate there diagnosis was because we don't know how much they really did! It sounds like you just got some codes read and some suggestions from them on what could be causing it and went and perfromed the repairs yourself. Often times this is not the best way to go about it. A code readout is not a complete diagnosis. Never has been never will be. When it works out it's luck based on pattern failures and odds. When it doesn't work out it is what it is! A guess, educated or not it's still a guess! First thing that comes to mind is vaccum leaks and low fuel pressure. Especially fuel pressure as I'd tend to think if it were intake gaskets the truck wouldn't be as gutless as you say it is! As well timing and exhaust back pressure need to be verified.