go to this link http://diy.prostreetonline.com/howto...p?articleid=31
it explains everything you could ever want to know about the SAFC and it also describes how to read o2 voltage with the safc which will help you tune the car.

 

relying on a barrowband o2 sensor (looking at the safc o2 voltage) is not a safe way to tune, especially for a newbie

 

*narrowband

 

i agree the narrowband does absolutely nothing and the 02 voltage does help but really isnt accurate enough for a good tune, even with the wideband its a really good way to tune but it still doesnt tell you everything either, like knock (which BTW the safc does not help with either). But dont get me wrong, the wideband is all you need if you know what a/f to stay around