Running stock cans with de-cat pipe


New Member
Hi all,

Like I just mentioned in the new members section I am the proud owner of a 2009 Fazer s2 with 1553 miles on the clock :Flash:

The bike is completely stock and I would like to make it a little louder, but I'm on a tight budget right now.

I'm thinking about removing the catalytic converter (from what I reckon, it's the honeycomb in the middle of the link pipe coming up before the seat) and maintaining the stock cans.

Will the bike be louder (while with a relatively pleasant sound) with this setup? Has anyone tried this mod with the stock cans?

Thanks in advance for any of your insights on this :D




Super Moderator
Elite Member
Site Supporter
:welcome:to our great forum!
I don't think you'll get the results you're looking for by removing the midpipe cat. From what I remember, I believe there are other cat materials in the main exhaust manifold on the S2 models. I've modified stock exhaust and although there is some improvement, it would just be better to try for a new or used set of cans.
Most of all the sound suppression is done in that big heavy can under the tail section. I've never heard a better sound improvement than getting rid of that undertail and replacing it with the many great units made for the FZ6.
Also when you start removing the cat, you may end up with less backpressure in the exhaust which usually results in people guessing how much to adjust fuel mix or having more expensive dyno tuning.

Gary in NJ

Junior Member
Site Supporter
I would gut the cans before gutting the cat. If you don't like the result, replacing the cat can be expensive - and you might not get the result you want.


Junior Member
Replaced the cat with a test pipe on my S1 with stock exhaust. No significant change in exhaust sound. S2 has additional cats in the headers I believe as well.


New Member
I bought a used mid pipe and cat for my S1 to experiment with this. I knocked out the catalytic element and installed the pipe, only thing I got was a tiny bit louder but massive vibrations. Vibration went away when the stock pipe and cat went back in.


2 Da Street, Knobs R Gone
Super Moderator
Site Supporter
The critical element missed with the OEM muffler when its innards get ripped out is that everyone leaves the outlet alone. And being thumb sized the velocity is high and all those sound waves are aligned with no freedom to bounce around and get crazy.

So, if you plan to open the OEM muff up for sound, take the next leap open the exits up to 25mm or more and it just might work when those hot gasses have a chance to expand into the atmosphere.

Or buy some used cans!

PS - see signature and search on my build thread for S2 mods. Going back in time has some advantages!