Here's my very first post, so might as well jump in the deep end. I had the cat go south on my '02 limited with 78k on it (the warranty on the cats goes at 75k, nice). After talking to as many folks as I could, including my usual mechanic who I trust, the decision was to put the stock Toyota cat on. I was told by the tech at a local muffler shop that he could put an aftermarket cat on for about $150, but had had repeat problems with Toyotas coming back for the Check Engine light. My wrench told me that Toyota is one of the few that the sensors don't like the aftermarket cats. It hurt greatly, about $1200 installed, but the concensus was that it would be the only real fix. The Check Engine light has not come back on since.