As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE MAINTENANCE TEAM DISCOVERED DURING POST FLIGHT CHECKS THE PILOTS OXYGEN MASK LEAKS WHEN INFLATED. THE MAINTENANCE TEAM REMOVED AND. REPLACED THE PILOT'S OXYGEN MASK WITH AN OVERHAULED UNIT. OPS CHECKS WERE SATISFACTORY, AND THE AIRCRAFT WAS RETURNED TO SERVICE.