In a matter of weeks a brand new shiny kfx/flyryde headers should be standing in my bedroom.
Now I'm slowly looking for a shop who can fabricate me a custom exhaust.

I also need a cat ofcourse. We have an annual inspection including emission testing.
And for our little lungs I want to keep it too.

But the most confusing part are the prices.
I've been on the forums for quite some time now and many of you recommend a Magnaflow high flow cat.
The prices are really good and supposely they work like a charm.

Cat's very from 60 usd (or less) to a couple of hundred.
Why is there such a difference?

Does a magnaflow really works or is it more to show that there is a cat?

And a 2.5" exhaust is not overkill on a N/A setup with just an AEM (coming soon) and the headers?
I'm going overaxle because of the high issues and the many speedbumps we have and I need 4" clearence for my garage to enter..

 

To kinda add to the questions, Is longer better?

AKA
http://www.greyhoundperformance.com/MagnaF..._1405-5412.html
vs
http://www.greyhoundperformance.com/MagnaF..._1416-5400.html

9 inch guts vs 15 inch guts...

 

Let me kick it