I was talking to the local performance shop and they told me that the cat will need to be shortened due to the length of the JDM DC. Is this true? If you use this header with the stock cat it is no longer removable from the header? TIA!!!!

 

true it does not bolt up to the cat due to it being 2.5in although it should come w/a adapter flange, your best bet is to get an a/m cat or shorten the b-pipe. modifing you stock cat in any way is illegal.

 

So if I get an aftermarket cat it will bolt on without any hassell? Do you know what brand cat is compatible?

 

I got my high flow cat from SMSP. Try to IM him. I also got a test pipe from him.
Both fit perfectly! Thanks SMSP

 

How do you feel about the gains with the test pipe? I heard they rattle sometimes, and the smell comes up inside the cabin. Is that true?

 

It doesn't rattle but it smells sometimes. when the car is moving I don't smell anything, it's only when I'm at a light and my windows are rolled down