[JFP in PA]

I really don't think you should be driving a car with a known bad AOS, and not because of concern over the damage it might do to the cats. The real issue is that a bad AOS can and do cause the engine to inhale liquid oil into the intake system, leading to a quick hydro lock and the need for a new engine (I have seen more than one of these). Once your suspicions about a bad AOS are confirmed, park it until it is fixed, it will be a lot cheaper than the alternatives................