As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED RIGHT PACK OVERPRESSURE, WITH LEFT HAND PACK DEFERRED PER MEL, AFTER DEPARTURE FROM DAY. CREW RETURNED TO DAY AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT AIRCRAFT, REMOVED AND REPLACED RIGHT PRESSURE REGULATING / SHUTOFF VALVE AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.