As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A NORMAL INSPECTION, BOTH FUEL STRAINERS WERE FOUND INSTALLED BACKWARDS. WITH FUEL FLOW IN THE WRONG DIRECTION, THE BYPASS ANNUNCIATOR WOULD BE INOPERATIVE. THIS WAS THE FIRST MAJOR INSPECTION OF THIS AIRCRAFT BY THIS FACILITY. THE PROBLEM WAS DETECTED BY THE CHIEF INSPECTOR. THE STRAINS WERE INSTALLED PREVIOUSLY BY PERSONS UNKNOWN.