As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT IDLE THRUST IN DECENT THE LEFT ENGINE N1 RAISE AND FALLS APPROX 10% W/THRUST LEVER AT IDLE. EACH CHANGE IS UNCOMMMAND. PERFORMED INTEGRITY CHECK ON WIRE PLUG ASSOCIATED WITH N1, FOUND DEBRIS ON CONNECTOR. CLEANED PER SWPM 20-60-01, WIRE CHECK PERFORMED PER AMM 77-12-01. RAN ENGINE, ALL N1 PARAMETERS NORMAL.