What was found
25 MINUTES AFTER TAKE OFF AT FL 370, CAUTION EICAS FOR LE SLAT ASYM, NO VIBRATION, NO CHANGE ON FLAP GAUGE, FOLLOWED QRH . NO ROLL OR VIBRATION DURING CONFIGURATION. DECLARED AN EMERGENCY. REMOVED AND REPLACED THE NR 2 FSEU IAW AMM 27-51-01-2, OK FOR SERVICE.