Welcome to the forum Brett.
This is the first I've heard of this problem. It could just be back luck, rather than a problem for them all. Did they say what failed?
So you never used a tuner to delete the emissions, you just cut off the exhaust? Also, removing the DPF will make the most difference in sound as it catches all the noise.
I asked in your introduction post how many miles, which I see here.
Glad warranty is in place.. did they give you a estimated time on replacement, or details on what happen?