So today i had a guy try and sell me an Apexi s-afc2 controller for my evo 8. I have my car steet tuned and its ecu boosted. I really dont know much about air fuel besides what is good and bad. My question is, is this contoller useful at all for any reasons? I mean i have mycar tuned so what would i do with this?? Also what would this thing be worth used?