As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE IN CABIN AND FLIGHT COMPARTMENT, SMELLED LIKE HOT DUCT. DECLARED EMERGENCY AND DIVERTED TO BUFFALO. AIRCRAFT FERRIED TO SBY. FOUND OIL IN HEAT EXCHANGER AND AIR CYCLE MACHINE DUCTING. REMOVED AND REPLACED ACM AND HEAT EXCHANGER. ON 15 APRIL PROBLEM RECURRED. ON GROUND RUN WHEN NR 2 ENGINE BLEEDS FLOW AT MAX AND MANUALLY SELECTING TEMP TO WARM, AIRCRAFT FILLED UP WITH OIL MIST. NR 2 ENGIND REMOVED AND REPLACED.