Haven't a clue whether emissions had anything to do with it, the manifold and cat were standard focus parts. As my car was the development car for the Blacktop I did suggest to Rob at Librands that it made sense to route the exhaust on the same side as the manifold and whilst there was no reason why that couldn't have been done as all the mounting points and holes already existed for the opposite side it was simpler and cheaper to keep with the original layout.
