what's the difference? is there an advantage for over the other? just wonderin...

 

cat-back is better because it starts behind your catalytic converter; wider piping from closest to your header is better (more air flow) ideally you'll want a header with approx. 2 1/4 piping from the cat (or no cat)

axelback is just a place to bolt on your exhaust...

 

i bought the 5 Zigen axle-back and got a custom made cat-back pipe. 2 1/4"

 

I thought the stock one was 2.5"? That would be funny as sh*t if you got a smaller one. Hehehehehe

 

no, the y's that go to the mufflers are 1 3/4 or 2", i belive. the part before the Y might be 2 1/4. i removed the resonator too. the stock pipe is ovaled from the cat-back to the Y. how come we always answer the same threads, Jrock?