Roadster Sport 3 Muffler and midpipe combo on NB - Help

routten · Postby **routten** » Tue Jan 05, 2016 7:31 pm

After a lot of delivery issues with TNT my Roadster 3 Muffler and Midpipe combo arrive today from MX5parts.
I am installing it to replace the stock exhaust on my late 2000 (NB8B) NB. The install is supposed to be from the end of the header back.
When I took the OEM midpipe out and went to remove the catalytic converter, it goes as one piece from the Cat, then O2 sensor then splits into two pipes and joins the header in a 3 bolt attachment. The Roadster midpipe is a two bolt single pipe attachment and includes the cat.
I have attached a couple of photos. One with the stock midpipe next to the Roadster, others of the existing cat back to the header under the car (no use taking it off).

Hopefully the guys at MX5 parts are back tomorrow, but if anyone has any suggestions in the mean time it would be appreciated.

Regie · Postby **Regie** » Tue Jan 05, 2016 7:37 pm

NB8B Cats are pretty much part of the header

NB8A cats are in the mid pipe, looking at that first pic is looks like you have a NB8A mid pipe

This is an aftermarket NB8B mid pipe in this picture

routten · Postby **routten** » Tue Jan 05, 2016 7:42 pm

Yes the Cat is part of the header assembly. That seems to be the problem.

routten · Postby **routten** » Tue Jan 05, 2016 7:57 pm

This is the style of header I have

routten · Postby **routten** » Tue Jan 05, 2016 8:31 pm

Thanks Regie.
You are spot on. Further research would indicate the Roadster midpipe/cat assembly shipped will only fit an NB8A. However the Goodwin racing and MX5 parts sites list the combo pack as being suitable for all NBs from 1998 to 2005 other than the Mazdaspeed MX5.
I'm sure the guys at MX5 Parts will have a solution for me tomorrow. Thanks again.