Hard to believe that all 3 cats failed, what yr. Is your vehicle and mileage? Hopefully covered under warranty.I'm having this issue all the time now. All 3 of my catalytic converters blew so they have been replaced, as well as the O2 sensors. Plus a valve adjustment and valve cover gaskets, new fuel injectors and new fuel feed pipe. They did tell me that my spark plugs were needing to be replaced....does anyone know if that would cause an issue and why those warning lights keep coming on?