As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO BOS DUE TO DIRTY SOCK SMELL. MTC PERFORMED TROUBLESHOOTING FOUND ODOR COMING FROM RIGHT ENGINE. PERFORMED BOROSCOPE INSPECTION FOUND BIRD DEBRIS COMPRESSOR STAGES 1,2 AND 3. SUSPECT BIRD STRIKE DEBRIS FROM PRIOR FLIGHT. MAINTENANCE FERRIED A/C TO MSP PERFORMED COMPRESSOR WASH. RAN ENGINES NO ODOR PRESENT. (LP# 6358966, 6358971)