its all good, most people dont know, but ill let you in on the REAL tuners most closely gaurded secret.
the thing is called a wide band o2 sensor. unlike a narrow band, it doesnt just switch on an off as it goes above and below 14.7:1, it tells you exactly where you are. If you monitor your tps and rpm in conjunction with the signal from that wideband, you will have the information you need to either tune your car for performance, gas mileage, or just to pass inspection.
Having the information is good, but then you need to know what to do with it. After you find someone with a wideband (or purchase one yourself....they are a smidgen expensive though) then you gotta change the maps in your ecu. Most of the people on this board do that by chipping their ecu (meaning removing the old chip, soldering in a ZIF socket to their ecu, and adding a new one with a new program on it). I would recommend staying away from things like the apexi VAFC or greddy emanage. They are called piggy back ecus, and the only time i condone their use are if there is NO WAY you can wire in an obd1 ecu.
So after we have our ecu chipped (btw, the p30/p28/p72/p06 are the most commonly chipped ecus), we need to write the program for the chip. Id suggest you use a program called crome (
< C R O M E >) to write your new map. Basically you can see what the map is doing at different manifold pressures and rpms. Basically, if your running lean at 5000 RPMs and 30% throttle, you can adjust that spot on the map to run rich.
This is just a quick overview, we have a whole lot of tuning write-ups (as does
pgmfi.org • Index page. I gotta go to work in a few, and going through a full write up aint gonna happen today....i bet you miss that carb screw right about now.