As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5542, IAH TO MOB - DURING CLIMB, THE CREW REPORTED THAT THE E2 VIBRATIONS WERE HIGH AND THERE WAS AN INDICATION FOR LOW OIL PRESSURE. E2 WAS THEN SHUT-DOWN AND THE FLIGHT RETURNED TO IAH AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE ENGINE AND FOUND A LOOSE B-NUT FROM THE LUBE AND SCAVENGE PUMP. THE B-NUT WAS RE-SECURED AND THE OIL WAS SERVICED. E2 WAS THEN RUN AND THE OIL PRESSURE AND VIBES WERE BOTH WITHIN LIMITS.