As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE TORQUE FLUCTUATION AT +30 TO -30 PERCENT ON CLIMBOUT. RETURNED TO SLC FOR NORMAL LANDING. ATTEMPTED TO FLY WITH EEC'S OFF, NO CHANGE. REMOVED AND REPLACED PCU ON LEFT ENGINE. OPS CHECKS, LEAK CHECKS GOOD. P/N: 782490-46 S/N ON: 900528 S/N OFF: 851019.