What was found
FLT#2433, DCA-PBI. 'LEVEL 2 FUME/ODOR EVENT - DISTINCT STRONG PERSISTENT ODOR DETECTED BY MULTIPLE CREW MEMBERS INITIALLY AT 18,000 FEET DESCENDING THEN AGAIN IN COCKPIT AT 4000 FEET. ODOR ISOLATION PROCEDURE APPLIED. ODOR DIFFICULT TO DETECT AFTER 5 MINUTES (PACK 1/BLEED OFF, X-BLEED SHUT); C/W INFO NOTICE 2017-T015L- INSPECTED APU AND FOUND POSSIBLE OIL. REF LP 4260582-2 PERFORMED ECS DECONTAMINATION PER MM21-00-00 REMOVED AND REPLACED CABIN RECIRCULATION FILTERS REF 21-21-41. ACCOMPLISHED ENG RUN-UPS NO ODOR PRESENT- NO PREVIOUS HISTORY - A/C OK FOR SERVICE REF TSM 05-05-00-810-805.'