Weird

[S13FX]

So I wired in my SAFC because im finaly starting my KAE-T project and the strangest thing happend. My car ran fine before the safc id ideld fine it drove fine, and it felt good mind you the engine has only about a 120k miles on. Now the funny part is after I put the SAFC the car runs even better.

Iv also had this little problem where It would back fire sometimes when I down shifted and it liked to burn rich a little bit, but thats cause my O2 sensor is shot to hell. So I set the SAFC to around -2 arcross the whole board and not only does my car have much better response it also dosent back fire and it seems like my fuel economy got better. Now I know I leaned it out when I set it to -2 but I never knew that 2% could make such a difference.

Also if I am running a SAFC do I really need a good working O2 sensor do i really need one at all?

Any input would be greataly appriciated.