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?
A lot of people are still shy about voiding their warranty on a $40K (or $50K in some cases) truck..
I'm assuming he's tuned his EcoDiesel's. So he should have some good info for us as far as gains, MPG gains, etc.