Anybody replace Catalayic Convertor with High FLOW one?
 

Anybody replace Catalayic Convertor with High FLOW one in their P5?

I have on my MP3.

Tell us more about this high flow cat where?How much?what kind?do you have to put a header on first or can you swap with stock cat?Thanks!:blue:

HELLO ANYONE THERE?

It's not a must to install a header, but if you are looking for performance you might as well save your money and do the complete system to take full advantage of the gains.
The exhaust manifold has a large flange for the 1st catalytic converter to attach to. I haven't seen anything to replace the 1st cat with the exception of a header. You could remove the guts from the #1 cat and use the stock manifold. The 2nd cat would be were you place the hi-perf. cat. While you are there you might aswell increase the exhaust pipe to 2 1/4" and add a muffler...cost would be minimal. Your exhaust system is only as good as it's most restrictive point. Bosal/BroSpeed has a cat back style exhaust system, they also do R&D so your not buying a basement bargain system.
If you were to install a cat back exhaust to a high flow cat, all you have to do is modify the catback system to match the output of the hi-perf. cat.(not the other way around, the catback system would probably be designed to match a factory cat.)
This is basically my idea for some of my next years projects (this year is interior upgrades).

Please don't phrase it that way. Restrictions in your exhaust system are additive. If you remove any restriction in your current system, even if it's not the most restrictive one, you still have a less retrictive exhaust then you did before.