Key words in bold. You didn't get those gains from the delete, you got them from the tune. Removing and disabling those systems isn't going to give you anything substantial.I beg to differ... I have a 2011 VW Golf TDI and have deleted the DPF and EGR systems. The results are amazing to say the least. My horsepower went from 140 to 200, torque went from 210 to 300 Foot Lbs. and my average fuel mileage went from 38 MPG to 43-45. and the general drivability (ignoring the power and torque change) is massively better. And.. it does not smoke unless you really get on it. I fully expect the same sort of results with any modern diesel with a properly done tune.
When I get my Gladiator it will all come off. Yes I am lucky to live in a no test area... It is My truck, not the Governments... I have no contract with the EPA to force me to comply.