Hi there!

I own two diesel S40 II cars: 2.0D 2004 and 1.6D 2005 .Last time I went to consult a DICE unit costed me a lot for something it didnt worth it...So I decided to buy my own DICE unit .I am not a mechanic but I am selling car spare parts,so I do know a little and I am also willing to learn...

So I got my DICE and I have some noob questions:
1.where do I get the normal values parameters at least for these 2 specific diesel engines?VIDA does give some normal intervals,but intervals are realy wide and I supose that's for all the engines.For example: Boost pressure "actual value" should have the range: 0-5,000 hPa acording to VIDA.But I have been told that pressure should be around 2500 at peak and 2200 at load for 1.6D which is what I usualy get...
2.EGR valve VS EGR position sensor? I am confused...how do I check if EGR is ok?what parameters I should check and what values should be normal?
3.is there any parameter that would show the load percentage of the DPF?
4.what paramaters and normal values for checking MAF?
5.how to check if my KM were modified by the ex owner?

For the moment these are the my questions!Thank you!