problems persisting after new HPFP! Help

[OC Stroker]

took my 6.4 into the dealer 3 weeks a go for loss of power and check engine code p0088 (fuel rail/system pressure) too high. tech said it needed a new hpfp and so they went ahead and replaced it. truck seemed to be ok when i got it back except whenever i got back into the truck after driving it for a while there would be a loss of power right when i started it up and got going. id get on the gas and it would just have no power but would then clear up pretty quick and start driving normal. this always happens everytime i get back into the truck and get going. now im getting a p0087 (fuel rail/system pressure) too low and p2291 (injector control pressure) too low-engine cranking. im not always getting a check engine light but i can feel the truck running funny and when i run diagnostics on the dashdaq, those are the codes its producing.

can anyone tell me whats goin on?