Do I need a cat bypass pipe?

[JohnnyB09T]

Jardines no longer made. There are other manifolds out there, high dollar don't include the mufflers usually. and there is no official cross-over on the market to keep the dual muffler look. We do make a cross-over which allows mounting of OEM, TORS and D&D mufflers. But due to lack of DYNO results no one is willing to take a chance. Video clip on YouTube which gives sound levels. Still looking to dyno and post to prove the KISS (keep it simple stup*d) system works until then PM me if interested. S/S and metal versions available. Or not.

 

[ThingKing]

CES Racing just did headers and a crossover for me, I got 17 hp out of it. The tune still needs to be improved, and I am hoping for another 6-7 hp.
http://www.r3owners.net/threads/rocket-science.18293/page-41

Also there are collector pipes on ebay: i.e. search for article nr 131480870770 there.