Mccormick009

Like the title says will a Mugen 4-2-1 exhaust manifold bolt up to a USA spec catalytic converter?

B_Swapped93

same as a stock 4-1 "jdm 98spec" header so yes it will.

Mccormick009

Thanks Swapped! I had heard rumors that I would need an exhaust job to make a special flange to fit...

B_Swapped93

nope, flanges almost NEVER vary, its the lengths of the manifold you have to watch. but most aftermarket ones state if its a "CAT delete" style

Mccormick009

Aah that makes sense. So the length of the Mugen will be a match! Awesome!

cisco_kid

iTrader: (2)

I thought mugen manifold had a 2 bolt flange while US cat has a 3 bolt... ???

B_Swapped93

you're thinking of the other side of the cat show me ONE 90's Honda exhaust manifold that has a 3 bolt collector...NONE of them do. the only other type of flange used on piping is V-band besides those mugen exhaust manifolds are nothing special.

Mccormick009

So I took some photos of the car with stock manifold and cat and it appears the angle of the flange welded onto the Mugen won't line up with the cat. Can the cat be rotated to fit or do I need a muffler shop to weld a flange?

B_Swapped93

test pipe...

or more rather a "telescoping test pipe"

Mccormick009

I would like to keep the catalytic converter. I dont want to mess with check engine lights all the time

HondaPartsHero

If you don't want to weld you could do something like this

https://honda-tech.com/honda-civic-d...eader-2843300/

EnjoyTheRideDC2

iTrader: (1)

What model Integra do you have?

Can you post these pictures you took?

The Mugen header is made with the JDM 2.5" collector... USDM collectors are 2.25".

The header will fit the B-series VTEC engine, but its not plug and play with a USDM Integra GSR (assuming you have this model.)