As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE REPLACED THE NUMBER ONE ENGINE PYLON INBOARD EXHAUST GRILL. MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE ENGINE PYLON INBOARD EXHAUST GRILL IAW EMB ETD2013-190-004333. THE AIRCRAFT WAS RETURNED TO SERVICE 3/14/2013.