Do you weld it onto the Y-pipe? Or somewhere else?

 

Had mine welded just before the over the axle pipe.

 

I put mine right after the Y-pipe in place of the cat. But if you have emmissions I'd put it right after the cat

 

ditto on that.

 

Mine is right after my ORP or where thhe cat would be

 

I had to pass emitions so i put it just after the cat...works fine....a little loud inside though.

 

I would install my cut-out in this location if I were you. http://www.dmhperformance.com/Photo_Gallery.html (first picture)
I wish I had installed in this location at first (I will soon have to change after electric cut-out install). It offers the best ground clearance and does not require a change if you add a electric cut-out.

 

could you put it before the cat? would it sound better?
BTW i dont have to pass emmissions.

 

That's exactly where I put mine. A nice rumble and not too much interior resonance.