When a diesel guy talks about an clean tune, we are talking about the soot mass because that is what people see. Of course the NOx would be off the charts and just about everything else. But of the states that smog besides Cali, they are just looking for soot, which many of the big name tuners stock tunes will pass. Just by turning off the EGR cleans up the soot. There are other things they do as well, trade secrets, to clean up the smoke. Interesting part is some also do emissions in place tuning, which with the right mods, results in fewer regens and more power. Believe what ya want dude, just don't go rolling coal on people like the moron you are.
