1jeep
HD will not be able to fix it because they can not. EPA restrictions. It is that simple.
The fix is simple too.
It is up to you to do it even as frustrating as that is.
Remove the cat...new head pipe or cut it out. Look at the pictures on this site, when you see the cat you will understand why the heat is there...it can not escape.
We have big air cooled motors with closed loop fuel injection. Closed loop fuel injection is a great when used on a water cooled motor that runs at optimum temp regardless of OAT, speed, load, etc.
We need air, fuel, and oil, to cool our motors. You have an oil cooler so you are pretty much done there.
More air flow will result in a more open exhaust.
More fuel will help via a tuner.
I suggested Fulsac because he is in AZ (HOT) and has done all the work for you. I did all the above but used an HD SERT on my 09 before Fulsac had all this available. If you do it like I did you are crossing your fingers you get someone who knows what they are doing with the tuner and the dyno.
The answer is simple but it is going to cost a little. I figure the money I saved by useing fulsac cores vs. the $500-$800 spent for slip-ons pays for the tuner.