As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MUSTY ALMOST METALLIC SMELL NOTED IN DESCENT. SUSPECT SOMETHING LEAKING INTO BLEED SYSTEM. TROUBLESHOT SMELL TO APU BLEED. FOUND OIL SCAVENGE LINES TO AFT BEARING ON APU LEAKING OIL. SECURED LINES AND CLEANED AREA. RAN APU AND PACKS TILL SMELL DISSIPATED.