1999 7.3 powerstroke, 4x4, automatic, Rough idle when warm, dropping icp pressure as low as 408, usually around 453-475 at idle when warm and 515-520 when cold(Runs great when its cold) stutters when decelerating coming through the 1000-700 rpm range. starts great every time, no long crank, no stalls, no lope, at least not after i replaced the idm. I'm currently getting approx 23mpg at highway, according to scangauge2, before pcm and exhaust install i was getting 15mpg (hand calculated)

Truck was not running when I bought it. 245k miles on it. I've replaced the CPS twice (gray), ICP Sensor & pigtail, IPR, unplugged and wired open ebpv, replaced 1, 2, & 8 injectors(because they failed CCT), new o-rings on all 8 injectors, new fuel pump, blew out fuel lines and cleaned screens and reconnected supply line at tank that previous owner had left disconnected, new fuel filter, new oil filter and change, rev-x oil additive in hpop resovoir, new hpop resevoir gasket, new mounting gasket and o-rings on hpop, new uvch harness, tightened rocker arm bolts, new idm(Old one had a bad miss in #3 injector, replaced it twice before checking the idm), new remanned PCM (MNM1), reinstalled stock muffler because i couldnt stand the noise and my speakers were all blown trying to compete with road noise, traced wires across drivers side valve cover, no wear. truck has manual GPR switch in cab, previous owner kept blowing the GPR. cleaned and checked intercooler tubes and boots, no apparent problems.

Truck runs good under throttle and was significantly improved by everything listed above, all thats left is this slight rough idle and stutter as truck decelerates(this is not a new problem, has existed since I bought it and got better when i wired open ebpv, tightened wastegate actuator, replaced idm & pcm, and replaced pigtail on ICP), if im decelerating with foot off pedal and start down hill and speed increases 3-5mph but throttle is not pressed the stutter will go away.

Fuel pressure under load at WOT never drops below 60psi, 70 at idle
14.1-14.3 volts on alt.
Lpop not checked but factory gauge shows normal
icp pressure WOT reaches 2800+/- at 42% duty cycle
at idle when cold icp 512-520psi at 12.5-14 % duty cycle
at idle when warm icp 408-476 psi at 9.8-12.5 % duty cycle
boost is only reaching 16psi max, cruising at 65-70 mph boost is 0-1psi (banks big head wastegate, readjusted a few weeks ago and wastegate is tight and closed unless actuated; stock garrett turbo)

Looking for suggestions. I'm leaning towards bad or stuck injector. All injectors now pass CCT and buzztest. periodically get icp pressure too low/too high code. If i unplug ICP sensor the idle smooths out, but the stutter under deceleration continues, just not as noticeable. Could my new icp sensor that replaced a sensor that was definitely bad, as tested in another vehicle, also be bad?, just not AS bad?

using ford diagnostic scan set at local diesel shop for buzz tests and CCT otherwise info is off my scangauge2 with xgauge.