Do I Need A Tune For A Tomei Cat Back Exhaust?


New member
So I am new to the amazing world of Subaru's.

I recently bought a 17' STI. completely stock with 30k miles.

Due to the warranty, I am limited to what I can do. I have been constantly calling the dealer who sold me the car asking what I can and can not do.

I was told and have in writing that a cat-back exhaust will NOT affect my warranty.

I really enjoy the look and sound of the Tomei catback.

I have had conflicting responses as to if I need a tune to run it.

Does anyone have any input on this?

Any and all help is appreciated.
Last edited by a moderator:


Diehard Car Enthusiast!
You do NOT need a tune for any CBE.

It won't change the flow characteristics, as that only happens when you swap out downpipes.

All you'll be doing is removing noise restrictions from the stock exhaust with a Tomei CBE, thus allowing you to hear that beautiful boxer rumble!