What was found
AIRCRAFT GROUNDED DUE TO ISSUE. REF LP428383, ITEM 3: AC VERY STRONG FUME EVENT. FUME EVENT BEGINNING IN AFT CABIN THEN FWD CABIN. LITTLE TO NO FUME IN COCKPIT. COMPLIED WITH "ELIMINATION OF ODOR" QRH. TURNED OFF PACK 2. PACK 2 OFF CLEARED FUMES IMMEDIATELY. EVENT BEGAN AT 12,000 FEET, ENGINES IDLE. CORRECTIVE ACTION: PERFORMED LEVEL B REMOVAL OF THE CONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM(ECS). STAGE 1 AND 2 CLEANING OF THE ECS GOOD. ALL OPS TEST GOOD. A/C OKAY TO CONTINUE. IAW AMM 21-00-00-615-803-A.