What was found
FLT 1229, EWR-CUN. DURING ENG RUN WITH NR 1 ENG AND NR 2 PACK. INFLIGHT IMMEDIATELY NOTICED SIGNIFICANT FUMES ODOR IN VICINITY OF ROW 22. INBOUND CREW HAD 2 FUME INCIDENTS ON INBOUND FLIGHT TO CUN. CREATING NEED FOR ENG RUN PRIOR TO BOARDING. ACCOMPLISHED LEVEL C DECONTAMINATION. IAW TASK CARD A2123038-2. THIS CLEARS MDDR # 608018. MX-4 UPDATED, PLACARDS REMOVED, MCC NOTIFIED.