As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY CHECK, APU EXHUST COLLECTOR CORRODED AROUND BOLTS AND SEAMS EXHUST LEAK ON SEAM. MX R & R CORRODED HARDWARE ON APU EXHAUST COLLECTOR IAW 20-10-01, REMOVED REMAINING CORROSION IAW SRM 51-12-02. PN NAS6703U2 BOLT. ACFT REMAINS UNTIL COMPLETION OF HEAVY CHECK.