Just one quick question, does the Tanabe Ultra Medlion bolt on to the Perrin Test pipe? I'm just checking, becasue I'm about to put on a downpipe and test pipe

 

I purchased the Helix test pipe which bolted in similar to my stock cat. I would guess that the Perrin test pipe has the same fitment as the stock cat so if your catback currently works with your stock cat, the perrin should work.