That right there <points up> You can do all the mods you want to a OBD2 car/truck but none of them are going to help much until you change the PCM to accept all the new input.
I had done 3" exhaust, elect fan convo, MSD ign box, MSD Blaster 2 coil, modded the intake, and TB. But didn't notice that big a change till I got a SCT from hemifever. Man did that wake the truck up.