What was found
CREW REPORTED A LEFT ENGINE MISCOMPARE MESSAGE DURING CRUISE. CREW REDUCED THRUST PER THE QRH AND CONTINUED TO STL AND LANDED WITHOUT INCIDENT. AN EMERGENCY WAS DECLARED AND THE EQUIPMENT DID RESPOND. MAINTENANCE INSPECTED AND FOUND THE LEFT ENGINES LEFT HAND THERMOCOUPLE HARNESS ELECTRICAL CONNECTOR LOOSE. MAINTENANCE CLEANED AND RE-TIGHTENED THE CONNECTOR. MAINTENANCE PERFORMED OPERATIONAL CHECKS PER CRJ 200 77-11-07-710-001. ALL INDICATIONS NORMAL. AIRCRAFT WAS RELEASED FOR SERVICE.