I just had my catalytic converter replaced (more on this later...). The mechanic said my AZ van (originally from NY or so I thought) had a CA catalytic converter fitted (why I cannot imagine). Anyway he said it had to be replaced by another CA cat otherwise some other piping had to be changed because the connecting pipes are different beween the two. Was he spinning me a yarn or is it true? Is there any way to find out where a van was first registered?

I found an interesting web page on cats which goes into great detail about them.
http://www.epa.gov/otaq/cert/factshts/catcvrts.pdf