First off, yes I'm new to the site but not to Rangers :) I just had a question about the cats on my 4.0I. A little backround on my trucks existing exhaust, it has cat back flowmaster single in dual out muffler. Seeming that it has 4 cats, I was thinking about removing the BACK TWO cats ONLY. Replace that first cat with a Y-Pipe and run it to the existing pipe with a sensor before the last cat. After that remove the last cat with a straight pipe and straight to my muffler. I've seen a couple posts but they were about removing all of the cats.. I was wondering the advantages and disadvantages about doing this..