As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CHEMICAL ODOR IN CABIN/COCKPIT. VERY FAINT ON GROUND. STRONGER AFTER TAKE OFF DISSIPATED AT CRUISE. FAINT ODOR RETURNED DURING DESCENT. STRONG ODOR DURING APPROACH. FOUND APU OIL OVERSERVICED. ADJUSTED THE OIL LEVEL. AIRCRAFT GROUNDED.