When mine goes into regen, white smoke comes out from under the truck and it smells like a self cleaning oven, I can't stand it, it's driving me nuts! I can't have the windows down or it will fill up the cab with smoke. I am going to do the tuner with the DPF delete to see if that will help. The truck has 66,000 mi on it and goes into regen every 40 mi or so, I do tow a 10,000 lb trailer daily, but it still should'nt do that so often, it's a royal pain in the a***, if you know what I mean.