What was found
DURING UNSCHEDULED MAINTENANCE VISIT TROUBLESHOT AN ODOR COMING FROM AROUND ROW 16 POSSIBLY FROM A BLEED OR PACK BECAUSE IT WAS ISOLATED NR 2 BY TURNING NR 2 BLEED & PACK ODOR WENT AWAY WHILE IN CRUISE FLIGHT. THE AIRCRAFT WAS REMOVED FROM SERVICE. COMPLIED WITH ETN #EM-72-034R4 ENGINE ODOR EVENT TROUBLESHOOTING SUPPLEMENT. NO DEFECTS NOTED AT THIS TIME WITH NR 2 PACK OR NR 2 BLEED SYSTEM. NO PARTS REMOVED OR REPLACED. THE AIRCRAFT WAS RETURNED TO SERVICE.