Hey guys, I just completed several upgrades including 190cc 75% over Warren injectors, new stand pipes, new oil rail plugs, new hpop stc fitting, airdogg 150, 4in mbrp turbo back exhaust, KC stage 2 turbo kit, custom tunes from innovative diesel, and arp studs and new head gaskets and now have a cylinder #4 contribution code. The truck starts and runs fine and doesn't have the code untill the truck warms up then it has a rough idle and no power. I have pulled the ipr and the screen is clean. The ICP is around 590 at idle and IPR is around 21% which seems normal. At WOT ICP was 2000 which seemed a little low and IPR was around 83% which seemed high. I hooked shop air into the oil rail at the passenger side valve cover and can hear what sounds like a leak toward the rear under the head on the driver side. I haven't made a connector to put power to the ipr valve while I'm pressurizing the system is this necessary? I also haven't pulled the #4 injector to check orings I just didn't want to pull a head stud nut unless I have to. Any help would be much appreciated the truck has been down over a month and would like to get it going after dropping all that $$ in it.