Originally Posted by Saki GT

Even with a cat you will get some ash and staining eventually, but it will be accelerated with a TP - keep a rag handy.



Like stated above, most people recommend Berk, but also from what I've read, there isn't much if any performance gain unless you have other modifications and tune. Also, fwiw, I've never seen a head to head comparison of cat performance, and afaik the OEM is engineered HFC and is not considered a bottleneck. Unlike most cars, the S2000 was engineered with performance in mind and there is not much gained by swapping out OEM parts.

Old thread but a good read imo - https://www.s2ki.com/forums/s2000-mo...-hfc-s-842575/