I have an F-150 4.2l V6 with a difficult issue to remedy. The truck starts fine, no misses...Idles strong at 950rpm. Once you press on the acclerator, it will bog down tremendously at around 2000-2500rpm (in nuetral). In drive...LOL it wont hardly move, like all the horsepower is suddenly gone. In nuetral, turn on the A/c, it bogs down to 500rpm and sputters. I connected my OBDII scanner, and I was directed to O2 sensors, IAC valve, and Throttle body pos sensor/MAF issues. I changed all of the following trying to remedy this issue.: 2-O2 sensors, IAC valve, catalytic converters, fuel pump, MAF sensor, throttle body postion sensor, both Engine Coolant Temp sensors, IMRC solenoid/switch, cam shaft pos sensor, plugs and wires, checked fuel pressure (with in specs), and a new PCM module. Any further Ideas?? I tried my best...I don't know what to do next. I have not got any codes thrown yet, but i have the same problem. Please some guidence....

 

A co-worker was having issues with a shutter at times, lack of power...etc...went through the heads, upper intake...and similar sensors as you.

ended up to be a cam position sensor ...but the trick is the cam position sensor needed to installed correctly...or in a correct position...or correct timing wise. once that was done it was all good, & his sprung back to life.

can't say that that is your case but you may want to investigate it, none the less.

 

You spent a lot of money guessing instead working on finding the cause.
A good scanner and knowing how to read the data would have exposed the issue.
If it is cam/fuel timing you could have saw that fact and taken only actions to correct it.
Better hope your doctor don't work on you like that or you might be 'born again'.
A low end 'reader' for codes won't yield such information.
No codes does not mean there are no issues , only that the program is satisfied with the feedback it gets.
Btw, idle of 950 is to high, as the first symtom and load down of the idle with A/C on, is not proper.
On chance it's just simple; power down the PCM to reboot it, then let it relearn. If the issue is not solved, then look at the CPS for proper installation adjustment.
Changing so many parts still leaves the PCM memory and operating tables with the old operating data until it slowly changes with long term number of driving cycles..
Good luck.