Yeah I get that part. The instructions for that were straight forward. But it also will monitor different systems like EGR,Misfire,o2sensor and heaters. That kind of thing, it will tell you how many systems are ready and how many are incomplete(INC).Then I think you can moniter one of those systems as you drive and then wahlah.It spits out some info on the display. I can't find it in owners manual or on their website. I am sure it will do these things I think. Just don't know how to do it. Thx.