I have a 2002 Quad Cab 4x4 with 5.9L and was wondering if anyone had a diagram of the stock exhaust. I have looked online and can't find an actual diagram, just a generic version. I looked under my truck, and the cat has been cut out and replaced with a pipe. i am just trying to figure out what I need to do to get it back to factory specs. I am throwing codes saying the cat needs to be replaced and its also hurting my MPG's greatly. I am wanting to go with a true dual exhaust...but doing so means I have to buy 2 cats right?