Help with 2004 powerstroke 6.0

[lets-fish]

Hello I am new hopefully all the experience here can help me out. My 04 f-250 6.0 is running rough when Idling and died after 15 minutes of driving. I had to wait about 10 minutes before it will start. I had a p0266 code and changed the number 2 injector now I have a P0284 for the number 8. The engine has 26,000 miles on it since the factory service warranty work in which they changed the no. 7 injector and the turbo and all the gaskets and such. the Ficm has 47.6-48 volts. the ICP looks good and passed the air pressure test. New fuel filters, New oil filters and rotela 15-40 with wix filter. Batteries are good and fuel is good. The EGR is also good on it and the EGR cooler is also good. Fuel pressure is good and oil pressure is good. Truck has some power when it is cold but still rough idle but when it warms up it looses power to the point where I can mash the peddle and it takes about 100 feet just to get to 5 mph. I am lost for words, what else it could be.