As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RIGHT FUEL CAP HAS AN INTERNAL GASKET BLOWN. NO EVIDENCE OF CONTAMINATION WAS FOUND AS A RESULT OF THAT. REMOVED AND REPLACED RIGHT AND LEFT WING FUEL CAPS WITH NEW P/N C156003-0101 (8130-3) I.A.W.TEXTRON/CESSNA 172 SERIES (1996&0N) MAINTENANCE MANUAL REV. 23 CHAPTER 28-20-00.