As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: VERY STRONG OIL ODOR IN COCKPIT AND CABIN FROM TOP OF DESCENT TO THE GATE. MAINTENANCE FOUND THE APU OIL TRANSFER TUBE ON THE FAN MOTOR LEAKING AND REPLACED THE O-RINGS AS REQUIRED. MAINTENANCE CLEANED THE FAN DUCTS AND THE APU COMPARTMENT. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.