What was found
LEFT PROPELLER RPM FLUCTUATES WHEN ENGINE ANTI-ICE IS ON. EXTENSIVE TROUBLESHOOTING AND COMPONENT REPLACEMENT DID NOT FIX THIS PROBLEM. REPLACED THE LEFT ENGINE.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
LEFT PROPELLER RPM FLUCTUATES WHEN ENGINE ANTI-ICE IS ON. EXTENSIVE TROUBLESHOOTING AND COMPONENT REPLACEMENT DID NOT FIX THIS PROBLEM. REPLACED THE LEFT ENGINE.