I was afraid of this, looking at the FSM I saw nothing with the exhaust besides an exhaust leak. He did tell me with the IR gun that it registered a considerable temperature difference pre and post cat. Luckily I live in a no emissions county so I will chop it just to be safe and build a O2 fouler.
One thing that stumps me though, is the stupid P0172 goes away every morning on my 6 mile drive to work and comes back when I go home for the day. when its gone the truck runs amazing, when it is lit it runs like crap. I am going crazy over this thing

hwell: