i went to this site http://shopping.lightningmotor...age=2

whats the map type i now what the map is for but whats 2-bar and 3-bar? my be a dumb question but im new to tuning...

 

The 2-bar and 3-bar rating is simply the pressure range that the sensor will read. A 2-bar sensor will read up to ~29 psi of pressure, while a 3-bar will read a maximum of ~43.5 psi. These are obviously only needed on forced-induction applications.