As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, F/A REPORTED TO CAPTAIN THAT THERE WAS AN ODOR IN THE CABIN. CAPTAIN SMELLED FAINT TRACE OF ODOR AND RETURNED TO GATE. FOUND FUEL LEAKING FROM NR 2 ENG TRANSFER TUBE ON FUEL OIL HEAT EXCHANGER. REMOVED AND REPLACED O-RINGS ON THE FUEL OIL HEAT EXCHANGER TRANSFER TUBES IAW Q400 AMM 73-11-01, OPS CHECKED GOOD.