As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMELL OF EXHAUST IN THE BACK OF THE HELICOPTER DURING FLIGHT. PILOT DIDN'T SMELL IT IN THE FRONT. AMT NOTES: INSPECTED ALL FUEL LINES AND FUEL VENT PORTS WITH ENGINE ILLUMINATION 100%, NO LEAKS OR FUEL SMELL DETECTED, AIRCRAFT RETURNED TO SERVICE.