[jcommin]

You do know that cat design, materials and elements differ from car to car and year to year. That's why the cat thives cherry pick the cars when they remove cats. Ther are books of their values.

Having said that, I won't be afraid of an aftermarket cat providing it is for the correct vehicle. I would keep the old cat too or atthe least get a scrap credit for it.

But the bigger issue brought up from the previous poster " why do you need to replace the cat and who is telling you to do that?" I see more of an O2 sensor problem than a cat.