Sounds like its misfiring. Misfires will show up as lean on the wideband. Assuming all sensors and such are working correctly, I would be looking for a weak link in the ignition system...check the plugs, coil pack specs, maybe the igniter..

As for the wideband jumping around...you need to work on your "tune" lol.

And for the knock sensor...what wire do you have hooked up to the SAFC for that? And what is the reading? 120 whats? lol. I know SAFC cant read knock on Mitsus and its about the same thing here I thought.