What was found
CREW REPORTED LAV SMOKE ON RED EICAS MSG DURING CLIMB OUT OF DTW, AND SMOKE/HAZE IN REAR OF CABIN. CREW DECLARED EMERGENCY AND RETURNED TO FIELD AT DTW. THE A/C LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED A/C PER EMB FIM, AND FOUND APU INLET DRIPPING GLYCOL, PERFORMED OPS CHECK OF PACK SYSTEM PER EMB AMM AND NO DEFECTS NOTED.