First, thanks for your replies.
Mike, I will check out the O2 sensors before I buy new cats. I just got the specs so I can back probe them and know what I am looking at. That said, I also found out that this was a known problem (cats failing around100K mile) with the suv. My understanding was Nissan covered them for 8 years(which doesn’t help me). Anyways, oddly enough when I was checking the specs for the O2 sensors it says to heat them up to 600 degrees… which is what the mechanic said the problem was both O2 sensors being the same temp… And I thought Oxygen sensors monitored oxygen, not temperature…
db4690,
unfortunatly I bought it from an auction, and only had engine/transmission warrenty. I knew the risk up front, and I took it. I could go on about the risks involved in everything, but in the end, it is what it is. I just have to man up and climb under. Good thing it has some ground clearance…