As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE, FLEW WITH PACK 2 ON PACK 1 OFF. STARTED TO SMELL OIL FROM THE AIR CONDITION AIR. TURNED OFF PACK 2 AND RAN PACK 1. THE OIL SMELL WENT AWAY. DEF PACK 2 IAW MEL 21-51-01-0-1. PLACARD INSTALLED ON PACK VALVE PB SWITCH. NR M422794 ASSIGNED. REMOVE AND REPLACE NR 2 PACK COALESCER BAG IAW AIRBUS AMM 21-51-16-03. THIS CLEARS M422794.