As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS EN ROUTE FROM PWM TO LGA AT 8,500. PASSENGER NOTICED OIL ON LEFT FLAP. ADVISED PILOT, PILOT MONITORED OIL PRESSURE. PRESSURE STARTED TO FALL. SECURED ENGINE AND LANDED AT MHT. NO INCIDENT. INVESTIGATION FOUND LOOSE HOSE NUT ON OIL PRESSURE RETURN LINE FROM WASTEGATE. ENGINE HAD 4.7 HOURS SINCE INSTALLATION.