hey guys i am a newb to hp tuners. i just bought the tunning schools gm tuning for beginners. I am putting a torqstorm blower on my 2005 gto. I bought the DPE 2.5 bar map sensor. Which OS do i use 2 or 3? I have not even loaded my stock tune with hp tuners. I am taking my time and trying to learn as much as i can before i start. I have seen GEN 3 speed density videos but no GEN 4.