Q: Fuel pump Check Engine Light issue with operational fuel pump

Code 47 (OBD-1) is the only code that pertains to "fuel pump related faults" in your car, so presumably that is the code that is recurring. If it is not Code 47, but rather a different code, that you are seeing, you might still have an unresolved fuel system problem. If the new fuel pump and circuit are all working as intended (no voltage drops, regulator working, pressure within factory spec., etc.), it would appear that the re-set of the CEL has failed.

The standard method to reset on NSX models is to remove the clock fuse from main relay box, located in luggage compartment on RH side, for approximately 10 seconds to clear all DTCs. This will also cancel radio presets and clock settings. Try leaving the fuse fully disconnected for half an hour. If that doesn’t work, disconnect the negative battery cable for half an hour. If that doesn’t work, the only way to determine if the PCM is indeed responding to a fault (that triggers Code 47) is to substitute a known good PCM. If the substitute PCM displays Code 47, it means that there is still an "issue" within the fuel pump circuit.

YourMechanic can dispatch a mobile certified technician, at any stage of this process to perform a Check Engine Light inspection and get this expeditiously resolved for you.