I am purchasing a jdm 4-1 header for an integra type R. I know the jdm 4-1 is longer than the usdm header but is it possible to just modify the stock cat and put a 2.5 inch flange on it in order to fit the jdm 4-1 and be connected to the stock integra exhaust. In addition, if I do this, would a comptech cat back bolt directly right on?

If I get a catalytic converter from carsound, which converter do I have to get in order to directly connect the header to the stock exhaust? Does the converter need to be modified to fit the exhaust?

Thanks for the input.

 

if comptech exhaust is made to fit same as itr exhaust, then no, it doesn't have to be modified, you could purchase an already made cat from smsp (thats his username), he places extra welds around it to help with rattle and it should be a bolt-on for jdm header.

keep in mind, stock cat will be a major bottleneck, so good part of hp gains will come from the carsound cat with jdm 4-1 header, don't even waiste money modifying stock cat.

 

I had to get a carsound cat when I put on my JDM 4-1