Apexi makes the most commonly used AFC for the celica (but I think it's only GTS).. either way, you should have a qualified shop intall it, and the benifit isn't worth it without Forced induction (you NEED something with forced induction, either a reprogrammed ECU or something to tell the injectors what to do, a turbo would FREAK out your ecu without it). There are 2 types, the first one feeds the ECU modified info based on a user tuned program, the second (and IMO safer)takes the data FROM the ECU and relays it to the engine with a modification from a program.
I think the second makes more sense and is safer, since the ECU is better equipped to read the info coming from the engine and the ECU just intercepts that info and sends modified info to the fuel injectors based on your requested air fuel mix for that RPM. These really take allot of know how to tune however, if you try to wing it you could blow up your engine or cause an engine fire (and as you probably know 1 engine fire is usually enough to total your car).
I looked into AFC for the GT a while back, there are a couple out there, but they need to be tuned by a qualified shop and I couldn't find one. I would like to know what my ECU is doing with my A/F mix though, just out of curiosity.
IMO the best way to manually reprogram your ECU is to drive it consistantly a certain way.. if you want better performance, drive it hard and the ECU will give you more fuel... that's what the "intelligence" that they advertise IS... it is programmed with simple AI that learns your habbits and adjust.
[ 04-29-2003, 10:43 PM: Message edited by: FX-MAN ]