As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU MAKING BACKFIRING NOISE. SKUNK SMELL IN FWD COCKPIT & MILD FUEL SMELL IN CABIN<[01] PERFORMED PROPER APU SHUTDOWN AND RESTART PROCEDURE IAW AMM 49-11-00. NO FURTHER BACKFIRING ISSUES. PERFORMED CONDITIONAL INSPECTION OF CABIN SMELL IAW AMM 05-51-56 AND 49-16-11 DRAIN MAST INSP. NO FURTHER SMELLS OR DEFECTS NOTED.