As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3958 DURING TAKEOFF THE CREW REPORTED, RECEVIED A "LAV SMOKE EICAS WARNING". THE FLIGHT ATTENDANT REPORTED SMOKE IN THE CABIN AND PASSENGERS SEATED AROUND ROW 11-14 REPORTED THE ODOR AS WELL. THE CAPTAIN ELECTED TO RETURN TO ORD AND LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE NR 2 ENGINE IAW AE WC 71-000-00. THE OPERATIONAL AND LEAK CHECKS WERE GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.