Leaning out and stalling once in Neutral
 

So ive got the 91 Redtop SR20DET, i was having issues with the T25 at 12-14psi the turbo was slowly losing boost, no leaks, i donno what the problem was, so i did some research and it sounded like i could run a larger T3 turbo with a FMIC and a top mount turbo mani and a Wally 255 pump if i ran under 8psi. so i installed all the new equipment T3 AR .50 Intake and AR .63 Exhaust turbo on the new Top mount mani at around 8psi with the FMIC, and a Atmospheric BOV, I also installed a AEM wideband, Anyways my issue is.....when i first start it up (cold) it idles really rough (lean), and then after like 5-8seconds it riches out to around 13.8-15.5:1 it bounces around alot. if i take it for a drive it seems to drive decently underboost it runs around 12:1 AFR but as soon as i come to a stop and put my clutch in it leans WAAAAAAAAAY out to like 17 then it riches WAAAAAAAAAAY out to like 9.5 and then it leans out and stalls i plugged off the BOV same thing happens i raised the idle screw from 650-700rpm to around 1200rpm and it still stalls, the rest of the engine is stock....super confusing, im reading 18-20 Vacuum to so no leaks. is it just being temperamental? is there something i can do to be able to drive it? or am i pretty much boned till i can afford some kind of tune?
thanks

its your BOV, you gotta recirculate it back into the intake

Even if we plug off the BOV hole will it still act like this?

there are a bunch of things that controls motor so first I'd would check on TPS, BOV, air leak, TB, spark plugs, coilpacks, AAC valve etc, fluctuation of AFR value is normal that means your O2 sensor is trying to get to the best AFR for the motor.
good luck