As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AIRCRAFT WAS IN FOR HEAVY CHECK. LEVEL 2 CORROSION WAS FOUND ON THE AFT LAV SINGLE SPLIT JOINT. MAINTENANCE REPLACED THE SINGLE SPLIT JOINT IAW EMB 170 CMM 25-42-03 AND AMM 20-10-01. P/N CDSP2200-3. A/C STILL OUT OF SERVICE FOR HEAVY CHECK COMPLETION.