Off topic, but that extra "O2" sensor I found was apparently a heat sensor for the EU market or something... got rid of it, new cat installed today, no more rattle!
I'm beginning to think I have a "grey market" vehicle - All these problems I'm having for someting that supposedly has 60K on it. Dealer's getting a call from me tomorrow, and I may have an investigation launched, as I've already replaced (needed to, not wanted): Serp belt, radiator, both hoses, water pump, TStat, fan clutch, both temp sensors, valve cover gasket, oil filter adapter o-rings and finally the cat converter just to keep it running decent. Oh, and the neutral safety switch. 60K? Probably not. Mech. pointed out the worn rubber on the brake pedal too.