Not sure if it would be the same for your trucks but I have a Scan Gauge II and it lets me know when I'm in regen. Matter of fact, I can watch my soot grams. It starts at 3 and when it gets up to 21 grams it goes into regen. It is a cool little tool to have. I was on my way home and it went into regen and was down to 9grams and when I got into the driveway. I sat there in park with the rpms at 2k until it went down to 3 and stopped. Needless to say I sat outside the garage but the door was open and when I backed into the garage and got out I could smell it inside the garage. 1 RGN is in regen, 2 RGN is complete and 0 RGN is not in regen. 19 STM is 19 grams of soot.