As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: APU SMELL IN CABIN. DURING DESCENT, BELOW 10,000 FEET, ENTIRE CABIN AND COCKPIT FILLED WITH VERY STRONG NOXIOUS ODOR. ODOR SMELLED OF OILY NATURE. MAINTENANCE FOUND APU OVER SERVICED. RAN BOTH PACKS FROM ENGINE BLEEDS AND AIRSTART CART. REPLACED APU PER JOBCARD 26L31049003.