As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/GSO - FLT 7403 - DURING CRUISE, AIRCRAFT DECLARED EMERGENCY AND MADE AN UNSCHEDULED LANDING AT IAD AFTER RT ENGINE CAPTION ILLUMINATED WHEN ANTI-ICE SWITCHED ON. MAINTENANCE REMOVED AND REPLACED RT ENGINE ANTI-ICE VALVE. OPS CHECK GOOD WITH ENGINE GROUND RUNS. AIRCRAFT RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)