As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LGA - FLT 0963 - EN ROUTE LGA/BNA, CREW NOTED FUEL VAPORS COMING FROM LEFT AND RIGHT WINGS. AIR INTERRUPTED BACK TO LGA AND LANDED WITHOUT INCIDENT. REPLACED COMBINED PROCESSOR TOTALIZER. PERFORMED OPERATIONAL CHECK OF AUTOFEED SYSTEM PER MM. SYSTEM GROUND CHECKED, NORMAL OPERATION. (X)