As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED ROUGH RUNNING ENGINE AT 2200 RPM SPECIFICALLY. INSPECTED ENGINE SPARK PLUGS, NO DEFECTS NOTED. CHECKED IDLE MIXTURE CUTOFF, NO DEFECTS. RAN AIRCRAFT ENGINE AND DUPLICATED PILOTS SQUAWK. PERFORMED CYLINDER #2 DIFFERENTIAL PRESSURE CYLINDER LEAK CHECK AND RESULTS WERE 62/80 AND AIR COULD BE AUDIBLY HEARD THROUGH EXHAUST.