APEXi S-AFC
 

I need you need to incorporate extra fuel with the more mods that you do. I was planning on putting an intake, a downpipe, and an exhaust. Would I need to provide extra fuel? If I have to, can I use something like the APEXi S-AFC instead of an ECU?

Don't use an S-AFC on your car. It modifies the boost signal to get more fuel, which will make you hit the fuel cut at a lower boost level. If you want something cheap, buy a used PFS PMC "purple box" piggyback computer. They can be found for about $500. I've got one if you decide you are interested.

Remapped ECUs from Pettit and M2 are affordable and plug-n-play, but not adjustable.

The best alternatives are Haltech, PowerFC, and the new AEM computer.

You would probably be at the borderline with an intake, downpipe, and cat-back exhaust (don't get a midpipe without a computer). Some cars run lean under those conditions, so you will see recommendations that 2 mods is the limit before you need a new fuel control system. However, I think the recommendation is pretty conservative, and there are a lot of cars that run fine with those three items on the stock computer. The best way to check would be to install the intake and downpipe and check your mixture with a wide-band O2 sensor (the stock one is not accurate enough). If you aren't still running really rich across the board, you should probably install a computer with the cat-back.

-Max