I recently pulled my HPOP and replaced my 2-piece fitting with an updated 1-piece. There is a kit out for this: 4C3Z-9B246-C. Since I already had my turbo off, I decided it was a good move even though I didn't have any problems.
I read somewhere, that usually the HPOPs are okay and it's just the fittings that are leaking. 2005+ they changed those fittings to a 2-piece SCT quick connect. What year is your truck? Perhaps they could try to replace the fitting?
While I was into the HPOP system, I didn't notice any ICP sensor. I obviously had to remove the IPR to get the HPOP out, but where is the ICP sensor? The 6.0 Bible isn't clear "exactly" where it is? Strange I didn't notice it while doing my job. I don't even remember any electrical connector to unplug (other than the IPR). Hummmm.