As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER PARKING AT GATE GROUND CREW INFORMED FLIGHT CREW APU STARTED THROWING SPARKS OUT THE EXHAUST. CHECKED ALL MAG PLUGS NO METAL FOUND. INSPECTED TAIL CONE, NO DEFECTS NOTED. ONE TIME FLIGHT TO HNL FOR CHANGE. REPLACED APU ASSY, LEAK AND OPS CHECKED OKAY.