I have never purchased any power upgrade for my truck yet. So I have never had a chance to read the fine print. What are the resrictions? I have heard yo have to sign a waiver to get some high horsepower programs? Do the manufactures specify certain programs for off road only? Is it illegal to run high horsepower tunes on the street? I see some picture of people driving on the street with enormus amounts of black smoke coming from there exaust pipe and it just makes me wonder what that is doing to our enviroment and also the reputaion of diesel trucks in general? In Colorado you have to put pay 40.00 dollars and have your diesel put on a dyno. and tested for emmission cleanliness. Will aftermarket items cause me to flunk this test? Also is there any longjevity issues asscociated with running these high horsepower tunes more freuquently than 8-10 sled pulls or quarter miles per year? I just wnat to know what I am getting into. before I purchase. Thanks in advance.