As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN AIRCRAFT WAS FLYING, A LOUD BANG WAS HEARD. MAP WENT FROM 27 INCHES TO 20 INCHES WITH NOTICEABLE LOSS OF POWER AND INCREASED VIBRATION. AIRCRAFT WAS LANDED WITHOUT DAMAGE. NR 2 ROCKER COVER REMOVED AND BALL JOINT OF EXHAUST ROCKER FOUND LAYING IN COVER. LOOKED LIKE PART HAD CRACK IN IT FOR A WHILE AND FINALLY LET GO UNDER STRESS. SUBMITTER RECOMMENDS MAGNAFLUXING PART BEFORE INSTALLATION.