It's weird that you couldn't get the codes. Anytime the CEL comes on, a code is stored, period.

 

DTC's are resetting because under KOEO conditions everything is fine. I would bet money on the UVC harnesses and if the main engine harness is fraying at the plugs should at least splice in the new pigtails if not just replace the whole harness (highly recommended). Pins are wore/ wires bad. Its the same concept as a bad ground on a battery. Have full voltage when no load but hit the starter (firing injectors) and everything drops to nothing.

Also I've had tons of trouble with off brand CPS sensors. IH dirrect ones are worth the money!