Holley sniper EFI motor suddenly revving uncontrollably when I blip the throttle

^^This, "back to basics." An engine MUST have AIR to rev. Whatever the sensors/ electronics/ fuel ratio is off the table, it MUST be getting air someplace. The big difference between EFI and carb is, that if you have an air leak, the O2 will crank up the fuel. But the AIR is what drives it.

Vacuum leak, PCV, loose "somethings", IAC is AFU, stuck throttle blades/ linkage, etc etc.