As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSENGERS IN AFT CABIN REPORTED SMELLING FUMES AFTER RT ENG START. RETURNED TO BLOCKS. CHECKED AFT CABIN AND GALLEY AREA. UNABLE TO DETECT ANY UNUSUAL SMELL OR ODORS WITH ENG RUNNING AT GATE. SUSPECT FUMES CAUSED BY ENG EXHAUST DURING START. ALSO RAN IFE CHECKTO ENSURE NO IFE COMPONENTS SHORTING OUT. ETOPS CATEGORY E: PROBLEMS WITH SYSTEMS CRITICAL TO ETOPS.