As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH- AT THE GATE THE CREW NOTED THAT A GAS FUME SMELL IN THE CABIN WITH THE APU RUNNING. MAINTENANCE DRAINED THE APU EPA TANK, PERFORMED A OPERATIONAL CHECK OR THE APU, NO DEFECTS NOTED AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.