As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PASSENGER OXYGEN SYSTEM FUNCTIONAL TEST OF A NEWLY INSTALLED SYSTEM IN A GULFSTREAM GIV, IT WAS FOUND THAT NUMEROUS PASSENGER OXYGEN MASKS HAD REDUCED OR NO FLOW. SYSTEM IS INSTALLED PER STC SA 1473S0 DURING INTERIOR OUTFITTING.