My 06 died on me while driving. I tried to restart but it wouldn't build sufficient ICP. Towed back home and replaced my IPR valve because I had one. The original IPR valve stuck in the bore but I was able to get it out with a small pick and then I cleaned out all the debris as best I could. Truck started right up after that but ran really rough. I drove it to try and work the air out and sometimes it felt like it was going to die. At idle, my ICP would drop as low as 300 psi sometimes but it never died. I kept trying to drive it and eventually it started running a little better but then it got a little worse again. Just more missing and erratic running. I ended up taking it in to a shop that had testing equipment. They determined that most of my injectors were bad which I was not surprised about as they had 235,000 miles on them. They tested checked the compression on all my cylinders and the lowest was 390 psi. They changed all my injectors and stand pipes and it always starts well but would have a miss until it got warmed up after driving it a lot. The technician wanted to chagne my engine oil just to see what that would do. I had been running a 10w-30 and they changed it to a 15w-40 and after that it has actually run worse. Misses more and always has a slight miss even after its been warmed up. ICP is always within 100-200 of desired and duty cycle ranges from 20% to 85% as they can change it with their scan tools. They think it is a problem with my high pressure pump as there was a debris on my ipr screen when I changed it. I know the 06 hpop are know to be very robust and don't fail very often but just wondering if anyone else has another idea of what could be the issue. It always starts fine and it runs better on a thinner 10w-30 oil than a 15w-40 oil and my icp numbers were very erratic and low after I changed the ipr valve. Neither the technician or I can think of anything else.