From reading the first post I would have said you had an injector or 2 with stiction issues or an FICM problem. This still will need checking as some problems mask or behave like other problems.
From your code, it is most likely a wiring/plug issue or you have a high pressure oil leak. I would recommend taking back the code reader and getting a good monitor (DashBoss, Scangauge II, or all-in-one programmer/monitor) or even an Auto-Enginuity with Ford bundle (diagnostic tool). The latter will help you the most if you plan on finding and fixing this yourself. You need to determine what your IPR is doing as well, but based on the code, the IPR is closing and the ICP is not rising to meet the demand. However, the IPR reading is not the actual position of the valve, it is the commanded position, so it will require more diagnosis to find the true problem.
Search out how to find a HPO leak. You will need to buy a M12x1.5 adapter to hook up shop air to help troubleshoot the HPO system.
FWIW, Today I put my Extreme tune back on my truck and when it was cold my HPO pressure would easily reach 4000psi. When I was driving down the road as it was warming up it was stuttering a bit at 1800 rpm until it warmed up. However, once warm the stuttering went away, but the max HPO I am now getting is 3000psi when warm. The power is also lower than expected. So it looks like I will have to track down a slight HPO leak and maybe a slightly off injector. I have no codes showing, so based on what is happening, I suspect it is related to a injector to rail seal, but it could be the standpipe and dummy plugs, the STC, IPR or even the HPOP. One thing to note is that with the stock or medium tune, the lower HPO does not show itself, making this probably harder to find. Since I will be doing some modifications soon (a different set of injectors (190/50), a turbo modification and perhaps the oil cooler (delta at 10*)), I will wait a while to rip into it, unless the pressure starts to drop. This is where the monitor will probably save me from being stranded or a road side repair.
Last edited by twoicebergs; 05-25-2013 at 02:23 PM.
Reason: my probable leak