As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#2 MAIN TANK FQIS FAILS SYSTEM TEST REF B737-800 AMM 28-4100-730-801. GROUNDED - YES. REMOVED AND REPLACED PROBES TU1, TU7, TU8 AND TU10. REF B737-800 AMM 28-41-21. ALL PROBES NOW WITHIN ACCEPTABLE LIMITS AND SYSTEM TEST GOOD REF AMM 28-41-00--730-801.