As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: STRONG ODOR OF MUSTY SOCKS ON TAKEOFF THAT DISSIPATED BUT STILL LINGERED DURING FLIGHT. MAINTENANCE FOUND THE APU OIL PUMP FILTER DIFFERENTIAL PRESSURE SWITCH LEAKING AND REPLACED IT PER AMM 49-91-14. A DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM WAS ACCOMPLISHED PER TASK CARD 26L00021014. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ODORS NOTED.