If you run stock fuel/timing settings in idle map, with stock o2 enabled (no air pump and single turbo) will the a/f's be in the stoichiometric range? or will it run rich?

 

(1) O2 FB is programmed to work with the air pump and stock exhaust manifold.
Left on without these two, it hoses your idle! Turn it off! As to being rich or lean is affected by your current timing & fuel and porting. Who cares as it needs to be retuned due to your mods. A WB will tell you the answer.

(2) You are forced to run stock idle timing unless you de-activate the ISC control by setting all three idle speeds to "0" with a Datalogit. If so done, then you have a manual idle control which now allows idle timing to be maximized.

 

Thanks much!