As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE AIR FILTER WAS CHANGED DURING ANNUAL. EN ROUTE, AIRCRAFT ENGINE RAN ROUGH. OWNER WAS ADVISED TO CHANGE AIR FILTER. AFTER NEW FILTER INSTALLED, POWER RUN DOWN RUNWAY WAS MADE AND ENGINE PERFORMANCE NORMAL. BRACKETT FILTERS BA 8103-1 REMOVED AND WAS REPLACED WITH A P10-6150 FILTER.