Good-Win Racing Mazda Performance Parts

BossFrog Straight Cat Larger diameter (test pipe) for AfterMarket Exhausts


Miata 1990-2005 · Exhaust · Catalytic Converter

Part Number: 10-1017b

Application: 1990-1993

Price: $75.00


BossFrog Straight Cat Larger diameter (test pipe) for AfterMarket Exhausts
rating (0 Ratings)
rating (0 Ratings)

Thank you. You have rated this product.

The Boss Frog "Straight Cat" is an unrestricted 2-1/2" pipe coupled with two heavy duty flanges that bolt right up to your exhaust in place of the stock cat.

Not CARB approved and never will be, legal for offroad race vehicles only.

YES, this will bolt up to anything your stock cat bolts up to, that includes stock exhaust and stock header and any of the aftermarket headers or exhausts we sell.

BRIAN'S APPLICATION NOTES: Unless you actually enjoy arriving home smelling like gas this is NOT a good idea for your street Miata. Also, please don't fool yourself into thinking you will get more power in your normally aspirated street Miata by going to a straight pipe. It was true three decades ago that the original pellet style catalytic converters were very restrictive, the modern monoblock core converters are NOT and making this change on your street Miata instead of using one of our highflow replacement catalytic converters is only going to get you the stench of unburned gas while you sit at stoplights.

Therefore, this mod is for the true racetrack Miatas and is legal for race cars only which may never be used on the highway.


Includes gaskets and mounting hardware. MADE TO ORDER, ALLOW UP TO 10 days to ship.

*** Product images may differ from actual product appearance ***


Roadstersport II was a great purchase, easy install, and sounds great.

-- Denny

Just wanted to thank you guys for the great stuff and great work done on my MX5 club yesterday. I could feel the difference in sound and performance right away! It drives and corners awesome now. Can't wait to tell my friends about you guys. I'll be keeping an eye on your web site for other goodies and events as well. Can't wait to try my new suspension out on a auto cross. Will definitely be trying it on some twisty roads this weekend. Just can't wipe that smile off my face when driving this car. Thanks again guys!

-- Paul Young