As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL400, NOTICED THAT THE ENGINE SYNC WAS NOT WORKING. NOTICED THAT NEITHER ENGINE WOULD DEVELOP FULL AND/OR NORMAL POWER FOR THE CONDITIONS. THE RIGHT ENGINE ALSO STARTED SURGING TO THE POINT THAT IT WAS NOTICEABLE THROUGH THE AIRFRAME. WITH THE FUEL COMPUTERS OFF, THE SURGING STOPPED, WERE NOT ABLE TO MAINTAIN MACH .71 AT ALTITUDE AS IT KEPT DETERIORATING. SWITCHED CONTROLLERS, DECLARED AN EMERGENCY. LANDED WITHOUT INCIDENT.