Q: Do I need an AFC or a piggy back system when I have installed the upgraded chip?
A: A lot depends upon the level of your mods, and how much boost you are trying to run. Although the changes I make to the Global Fuel and MAS Compensation are very close, making it much easier to tune, it is still recommended that you have some form of tuneability, such as an Air Fuel Computer or a GOOD adjustable Fuel Pressure Regulator. Do you run different octane fuels at times? Do you have an upgraded fuelpump, but stock FPR? Running >20 psi of boost on pumpgas?
Q: Do I need to upgrade my injectors?
A: The best way to tell is to watch your injector duty cycle on a logger. RC has a nice injector calculator: www.rceng.com
I sell the popular FIC Delphi injectors, and throw in FREE shipping when you buy a chip or upgrade! http://www.dsmchips.com/fic.html