I want to know what is the best off road Y-pipe to get with no cats that will fit the stock exhaust manifold and magnaflow 3inch catback? I heard that cats actually rob much needed power.

99 SS A4 magnaflow catback, sphon subframes and strut, trans-go shift kit, 373's, whisper lid 13.3 @ 106 1/4 (i know it can do better)

 

dont quote me on this, but not so sure there is a ORY out there for the stock manifolds. getting headers and an ORY is your best bet. or even taking the stocker off, gutting the cats on the stock Y and welding it back together. but yeah cats create extra backpressure that can rob HP, but you still need some. especially for a stock motor. but who am i to talk? lol i did the same thing. it just sounds so D@mn good!

 

JEGS part number 555 31052 seems promising

in the description it says it hooks up to the manifolds (no mention of headers) and says that it recommends getting a JEGS cat-back for the full advantage. sounds to me like it's a direct replacement for the stock y pipe.. but without the cat

 

yes, in the directions it says it uses the stock exhaust and manifolds.. for 179 it's not too bad!