As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENGINE LIMIT SURGE / STALL OUT OF APPROX FL220 OPERATED ENGINE AT REDUCED THRUST TO LANDING. DIVERSION TIME 27 MINUTES. LEFT EEC LOGGED ENGINE EXCEEDANCE OF 111.3 PERCENT & 106.6 PERCENT N2. ALSO LOGGED FAULT CODE 73 20331. FMU DEMAND & POSITION SIGNALS DISAGREE. REMOVED AND REPLACED NR 1 ENG PER TC 78471000 AND 78471001 WO 98528.