As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT, THERE WAS A FOUL MUSTY ODOR COMING FROM THE AIR VENTS. REPLACED RECIRCULATION FILTER IAW AMM TASK 21-22-22-000-801 AND 21-22-22-400-801 AND REMOVED ODOR FROM THE AIR CONDITIONING DUCTS IAW AMM TASK 21-00-00-160-801, CABIN SMELL NORMAL, CHECK GOOD.