As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - DURING FLIGHT 3998, THE CREW REPORTED SMOKE IN THE COCKPIT AND CABIN. THE CREW RETURNED TO IAH WHERE THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NR 2 ENGINE, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE. (M)