i have a 02 gmc duramax that makes a nocking sound when running. it get strong the more rpm. could it be injectors, fuelpump, or even valves?
it has a edge juice and programer it is als striaght pipe 4" exhaust
the thing pulls good and runs very cool on egts this sound buggies me when your driving with no radio on it almost sound like a power stroke

thank josh

 

guessin injectors, the knocking noise could be the slow or laggy solenoids in the injectors. i replaced mine cause they were bad and the "powerstroke" rattle went away.

if ur gonna replace them adjust the valves too while your down there.

but id get the balance rates checked and test out the cp3 with a tech II or efi live if it can keep up with rail pressure demands