As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH, MUSTY SOCK ODOR COMING FROM BLEED SYS, ODOR WAS WORSE AT LOW POWER SETTINGS. REMOVED AND REPLACED RECIRCULATION AIR FILTER. REF AMM TASK NR 21-22-22-000-801 AND 21-22-22-400-801. OPERATED RECIRCULATION FAN FOR TWENTY MINUTES. SMELL DID NOT RETURN. RETURNED TO SERVICE.