As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ANNUAL INSPECTION, THE SPARK PLUGS, RHM40E WERE CLEANED AND TESTED AND ONE OF THE NEW PLUGS THAT WAS INSTALLED 12 MONTHS AGO DURING THE LAST ANNUAL AND NOW HAS 14 HRS TT SINCE INSTALLATION, THE PLUG FAILED THE INTERNAL RESISTANCE CHECK: THERE WAS NO CINTINUITY THROUGH THE PLUG AT ALL. THE PLUG WAS RETURNED TO MFG FOR REVIEW OF THE FAILURE OF A VIRTUALLY NEW PLUG.