Exhaust stack separation

Is your muffler still intact? I think as long as your exhaust does not leak under your cab/sleeper it is a legal exhaust.
I had an inspection a couple months ago in MO. I have a leak around the bracket that holds the heat shield on muffler by Driver door. I was told it was ok. But I was given a warning for a pin hole leak covered with soot just under cab by passenger side.

 

Wise one says " replace whole exhaust system from turbo to exhaust tip". I recently did . Rig runs better. It's roughly 12hrs of hard work.. Advise getting a pit power muffler, turbo blanket, exhaust heat wrap.. Stock mufflers have a back pressure plate that doesn't allow engine to breath right.. Also u don't need the back pressure plate. The turbo S pipe creates one..

 

I like the Walker Megaflow mufflers. Same idea as the PP muffler, but a far greater warranty.

http://www.walkerheavyduty.com/en-US/products/mufflers/mega-flow

I got a pair of them for my Columbia dual stacks for around $115 a pop from Summit Racing.

I recommend the PTP turbo blankets over PP. Just as good of quality, but at a considerable cost savings. I took off the stock waste gate turbo and put on a Borg Warner 171702, that when I ordered it, was $624 shipped. The PTP T6 blanket does a great job on this turbo. $165 compared to PP $327.

http://ptpturboblankets.com/T6-Turbo-Blanket-Black-000509.html

 

The cold air will make metal contract. Your pipe would have came apart anyway from the rusting.