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NB 2.25" Flyin' Miata naturally aspirated midpipe and catalytic converter

NB 2.25" Flyin' Miata naturally aspirated midpipe and catalytic converter
NB 2.25" Flyin' Miata naturally aspirated midpipe and catalytic converter
Replacement midpipe for more power on normally aspirated cars. All stainless steel, lifetime warranty and a high-flow cat.

Made in the USA

Exclusive to Flyin' Miata

Availability: In stock



A full stainless replacement for the restrictive factory midpipe and catalytic converter. The 300-cell ceramic catalytic converter has a 5 yr/50,000 mile warranty on the housing and 25,000 miles on the internals, everything else is covered for life. Warranty details. Our midpipe includes a slip joint to make it easy to get the perfect fit and to cut down on your shipping costs. Works with all factory undercar bracing.

Help us recycle and get $20 back if you ship us your old original equipment catalytic converter. It must still have the ceramic core in it, doesn`t have to work. OE cats only. To save on shipping, you can cut the cat out of the midpipe.
Naturally aspirated Miatas should use this 2.25" version which is resonated. Miatas with aftermarket turbos should use our non-resonated 2.5" unit. Not compatible with the stock rear muffler on automatic cars. We do not recommend using this midpipe with a supercharger and aftermarket header due to sound levels.

The FM midpipe flange and the factory muffler flange use a different gasket in order to seal the exhaust system. We are aware the seal is not perfect when used with factory parts and we found the best seal can be obtained by using the factory donut gasket. This imperfect seal will not be an issue with a Flyin' Miata muffler. Please note that these are not CARB legal and we cannot ship them to California.

Not compatible with the 2004-05 Mazdaspeed turbo car.

Additional Information

Additional Information

Part number M06-58100
Fits: 1999, 2000, 2001, 2002, 2003, 2004 (non-MSM), 2005 (non-MSM)
Manufacturer Thermal R&D
Flyin' Miata exclusive Yes
Fits Exocet? No
Proposition 65 Warning: Cancer and reproductive harm
California emissions Not emissions legal in California

Customer Reviews 4 item(s)

Quality growl and revvy
Bought this along with the FM muffler, I'm waiting till the headers come back in stock. My cat was rattling up a storm, which caused me to blush redder than my car's paint... so I thought this would be a great opportunity for an upgrade. I can't tell any significant power-gain from the butt-dyno, but the car definitely breathes more easily and sounds great. I don't know if it's the muffler or this package, but the car sounds a LOT meaner than before, through all the rev range. It has a great deep bassy drone under 2.5k rmp with the top down, that's my only complaint. Has a great yell at higher rpms. (It's so hard not to floor it up to 6.5k rpm on the straights now cause it sounds so good up there!)

Install: I so desperately wanted to do it on my own, but I didn't have good enough tools to take the rust-eaten bolts off the original exhaust. Heck, even the shop had difficulty. Once they got the old exhaust out, though, the new one fit in remarkably well with little drama.

So, good sound (just loud cabin at low rpm), good fit and install, and seems to have let the car breathe better. Also, no problems with leaks that I can hear (yet). Keeping my ear open, but nothing seems wrong.
Review by Wyindy / (Posted on 5/24/2018)
Pretty solid
Good quality product. Did not have an issue with pin holes in the welds or anything. Only issue is that the slip joint doesn't seem to seal 100%. I've gotten mine close enough for my needs. I also have a different aftermarket muffler from Enthuza, so I also have a small (larger than slipjoint) leak there.
Review by Brian / (Posted on 1/26/2017)
Check all welding seams for holes.
Easy to fit with 2 pc system. Gets 3 stars because the welds had 2 pin holes that were found after installation. Had to remove and have repaired, then re-install PITA!
Review by Barley Pop / (Posted on 12/7/2016)
Quality product as usual
I already had the racing beat header just needed this part and the muffler. SOUNDS AMAZING. Def feel a power gain after these additions.
Review by CRNRHRD / (Posted on 4/17/2016)
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