JDM cat-back and downpipe question

[dustinhurley]

Can I buy an RSX-S downpipe/catalytic converter and bolt it between the USDM header and a JDM cat-back exhaust? I don't want to have to cut/weld my stock downpipe.

[dustinhurley]

Well, I did some more research. The part numbers for the RSX-S exhaust manifold is the exact same as the part number for the base RSX. So, this means the RSX-S cat/downpipe should bolt to either one of the manifolds. Next question.....the part number for the Civic Si manifold is different from the base RSX manifold, but it is the same motor. Is the number different just because of the Honda/Acura difference? It seems to me that the base RSX manifold should bolt to the Civic Si motor, since it is the same motor. Please help me out.

edit: If stock RSX-S manifold is same as stock base RSX manifold, and an aftermarket base RSX manifold is same as aftermarket Si manifold, wouldn't that make the stock base RSX manifold the same as the stock Si manifold? But why then would there be different part numbers for an aftermarket RSX-S manifold and base RSX manifold?

edit#2: Simple question, Is the Civic-R header and downpipe/cat the same as the RSX-S header and downpipe/cat?