As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH-FLIGHT 3422 DURING CLIMBOUT THE CREW REPORTED SMOKE IN THE CABIN, WITH RIGHTHAND DUCT LEAK WARNING. THE NR 2 ENGINE WAS SHUT DOWN AS A PRECAUTION. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE WATER SEPARATOR O-RING, PERFORMED AN OPERATIONAL CHECK OF THE PACKS SYSTEM WITH NO DEFECTS NOTED. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.