People say that you can still pass with only one cat, but I've never seen any proof. As far as I can tell, removal of cats isn't very common in New York. Bedabi has an up-pipe, and may have even had his emmissions tested since then. Any comments Bedabs?
I have one cat in the downpipe, which IMO is the cat that does the most work. I'm not due for an inspection till April, when emissions will be tested. This will be my second. You're exempt from emissions testing the first year.
Really, it's a matter of finding a place that does a half-ass job and making SURE that you go there only after your pipes and cats are real hot. Drive around the block a few times with the turbo engaged, and I think you'll be fine with just a downpipe cat.