As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RNO - CREW REPORTED LEFT ENGINE FUEL FILTER BYPASS LIGHT ILLUMINATED. EMERGENCY DECLARED FLIGHT RETURNED RNO LANDED WITHOUT INCIDENT. PLACARD LEFT ENGINE FUEL FILTER DIFFERENTIAL PRESSURE WARNING SYSTEM PER MEL. REPLACED LEFT ENGINE NUMBER ONE FUEL FILTER AND PRESSURE SWITCH AT ORD ON 01/30/2013. SYSTEM GROUND CHECK NORMAL OPERATION.