As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 1026, TPA-CLT: ON TAXI OUT, CABIN BEGAN TO FILL WITH SMOKE AND THE LAV SMOKE DETECTORS BEGAN TO SOUND. FLIGHT RETURNED TO GATE. MAINTENANCE FOUND THE APU HAD CONTAMINATED THE A/C SYSTEM WITH OIL. ACCOMPLISHED DE-CONTAMINATION OF AIR DISTRIBUTION SYSTEM. NO FURTHER FAULTS.