As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EWR - FLT 0400 - THE NR 2 ENGINE PARAMETERS BEGAN TO FLUCTUATE WHEN CLIMB POWER WAS SELECTED. THE AUTO THROTTLE WAS DISCONNECTED, BUT THE PROBLEM REMAINED. THE AIRCRAFT WAS RETURNED TO EWR WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NR 2 ENGINE FUEL CONTROL UNIT (FCU) AT FAULT. THE NR 2 FCU WAS REMOVED AND REPLACED. THE NR 2 ENGINE WAS TRIMMED IAW MM 71-00-00 AND ALL PARAMETERS WERE NORMAL. (X)