i put a edge juice with attitude on my friends 05 duramax and it was working fine for a few weeks but now it is running good until i get on the highway and punched it, it derates the engine and drops to 60mph and wont rev up. it has p0193 and p0194 codes but no cel. i am at a loss i am leaning towards the FPRV is dumping fuel. the rail pres. will stay at 9kpsi for a while then it will go away and run fine until the next time it happens any suggestions i will be diagnosing tomorrow afternoon, any help would be greatly appreciated