As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE AIRCRAFT HAD SMOKE IN THE CABIN DUE TO RESIDUE BURNING OFF FROM AN OVERNIGHT ENGINE WASH. THE CREW RAN QRH AND RETURNED TO FIELD FOR MAINTENANCE. THEY DECLARED AN EMERGENCY. MX PERFORMED HIGH POWER DRYOUT RUN TO CLEAR COMPRESSOR WASH FLUID FROM ENGINES AND PACKS. NO FURTHER SMOKE SMELLS NOTED.