What is gained by removing the EGR & DPF? For the EGR system some of the exhaust is cooled and then sent back to the engine. With this engine exhaust you will have less fuel burned do to the lack of oxygen in the cylinder to burn the fuel during the compression cycle. But more soot will enter the engine air intake due to the cooled Exhaust gas that is sent to the engine. If the truck is driven in short distance you will have oil changes between 3K and 4K instead of the 7. 5K as advertized, more soot and fuel in oil due to the duty cycle of your driving.
The DPF has no effect on the engine except to burn off soot from the exhaust cycle. What does happen with most active regens take place is to use fuel from you fuel system to burn off the soot when actively regening. Thus lowering your fuel mileage, now if you do a lot of long distance driving the ECM will use more passive regenerations instead of active regening so fuel mileage should not be harmed as much.
Is this done only to alleviate turbo clogging problems, or mainly for fuel mileage, or power upgrades? If you use the exhaust brake all the time than you should not have any turbo issues with or without deleting anything. Most deletes are done to improve fuel mileage and to eliminate harmful soot from entering the engine. You can also increase HP to the engine but some tuners will do this regardless if you are deleted or not.
What is the effect on emissions, does it now blow smoke in stock form, or with power upgrades? I can only speak for the Smarty but I have not seen any smoke on the mild tunes regardless of being deleted or not. I would fail an emission test if tested but my state does not test for diesel emissions.
Now the biggest question, with the present dictatorship will the EPA start mobile check station to fine people for the emission deletes? If these changes cause $25,000 fines from emissions Nazis what have we gained from fighting the man? Oo. That is the $25,000 question but I have not read where that is taking place all though I think Calf would be the first. I am a member of SEMA and I keep looking for post from them on the emission status in the US so far no change in the present policy. I would suggest that if you do delete that you keep the emission equipment for reinstallation if needed in the future.