So is it correct to assume that Tunerpro RT is something that I can really screw my original program with if I hit a wrong button? Should I read with WinALDL then go to another then go throught it with Tunerpro RT program to modify the program?

I am just at the beginning of figuring all of this out. have been a diesel fabricator for a decade, just now starting to take the 'nerd' step!

FYI: I have an 89 gmc v1500 and an 02 chevy trailblazer with an inline 4.2. I got so pissed off at tbi I removed it from my 88 dodge ramcharger and installed a four barrel, then I decided to learn more about it. My dad always told me that hindsight is 20/20, never realized what he was telling me until now!