As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE SURGES AT HIGH ALTITUDE. THE SURGES OCCURRED ABOUT 3 MINUTES APART AT FL 450 & A VIBRATION WAS OBSERVED BY THE CREW. SHORTLY AFTER, POWER WAS REDUCED TO BEGIN DESCENT. IT WAS NOTICED THAT THROTTLE WOULD NOT INCREASE POWER ON LT ENG, BUT WERE ABLE TO LAND WITHOUT INCIDENT. ECU B REPLACED.