As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT RPM IS WANDERING UP AND DOWN 2 PERCENT MOSTLY IN DESCENT ANYTIME THERE IS A PITCH CHANGE, RPM CHANGES, OCCASIONAL VIBRATION FROM LT PROP. INSPECTED LT ENGINE RIGGING AND PERFORMED OPERATIONAL CHECK OF ENGINE ON GROUND, OPS CKS GOOD. ENGINE PERFORMING WITHIN NORMAL PARAMETERS.