AIR/FUEL CONTROLLERS

What does an air/fuel controller do? Why purchase one?
An air and fuel controller is essentially a piggyback controller that allows you to interface with the factory ECU. The factory ECU remains in place and continues to handle all the engine’s functions, but an air/fuel controller relies on an altered signal to manipulate the ECU into changing the factory fuel and ignition maps. When you buy an intake, header, or exhaust or any combination thereof, your vehicle’s factory air/fuel ratio will be thrown off. To get the most power out of your car an air/fuel controller should be used. For example, when you purchase larger injectors, they might be spraying too much fuel so you'll need to lean them out, which is done with an air/fuel controller. By tricking your ECU into adding more or less fuel to the amount of air coming in, you can get more power out of your modifications, and it allows your vehicle to "support" more power.

Do air/fuel controllers work on every vehicle?
An air/fuel controller will work for your car if your vehicle’s ECU has a mass air flow sensor (or manifold air pressure sensor), rpm, throttle position sensor and O2 sensor.

What other aftermarket products should one have on his/her vehicle in order to maximize the benefit of an air/fuel controller?
Having aftermarket performance modifications such as an intake, header, or exhaust would maximize the benefit of the fine-tuning that an air and fuel controller provides. Factory or aftermarket turbochargers where the boost is raised, more aggressive camshafts, and fuel injectors are other types of performance parts that would yield gains from being tuned with an air/fuel controller.

What is involved in installing an air/fuel controller?
Air/fuel controllers are relatively easy to wire; a novice can install one of these controllers with basic hand tools in less than two hours. Wiring into your ECU is required and should be soldered.

Which brand is dependable for air/fuel controllers?
Apex'i has an S-AFC that is extremely simple to use and has a nice heads-up display that mounts inside the cabin so the driver can adjust on the fly either while driving or on a dyno.