I'm about to buy an isis o2 housing, test pipe and downpipe. I'm wanting to use the oem axel back exhaust cuz I've been told that part of the exhaust is more than adequate. I don't want anything overly loud as well with is another reason I'm wanting to stick with the oem muffler and tips. What I'm wanting to know is if the downpipe will bolt right up to the muffler or if I will need to have something modified to make it all bolt up. If anybody knows please chime in and give me some input.