As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF FROM EWR SMOKE ENTERED THE CABIN AND THE LAV SMOKE DETECTORS ACTIVATED. THE AIRCRAFT WAS RETURNED TO EWR WHERE IT LANDED SAFELY. THE SMOKE DISSIPATED RAPIDLY ONCE ON THE GROUND. THE AIRCRAFT TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE FOUND OIL IN THE NR 2 ENGINE BLEED DUCTS. THE NR 2 ENGINE WAS REMOVED AND REPLACED. BOTH COALESCER BAGS WERE REPLACED. THE ENGINE WAS RUN AND OPERATIONAL CHECKS WERE GOOD.