As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) SMOKE AND FUMES EVIDENT IN CABIN. INVESTIGATION COULD FIND NO CAUSE BUT THE LT HEAT EXCHANGER HAD BEEN REPLACED PRIOR TO THE FLIGHT. THE AIR CONDITIONING SYSTEM WAS OPERATED ON THE GROUND FOR TWENTY MINUTES UNTIL THE SMOKE/ODOR DISAPPEARED.