As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ENROUTE PASSENGERS SMELLED A BURNING ODOR COMING FROM THE FORWARD PASSENGER SEATING AREA. THE ODOR WAS COMING AND GOING AND HAD AN ODOR OF BURNED INSULATION OR WIRING, DIVERTED AIRCRAFT. INSPECTED WIRING BEHIND THE METER CONTROL PANEL AND FOUND NO EVIDENCE OF BURNED WIRES, CLEANED COALESCER SOCK IAW MM, RAN AIRCRAFT NO FURTHER ODOR DETECTED.