[urq] Sudden lean running 10v

[Mike Del Tergo]

Ihad the engine pulled last fall to clean up the engine department and drop in my rebuilt rack. Finally got a chance to play around with it after the engine went back in and had a lot of electrical connections to correct that the wrench was not sure of.  I have had an O2 in it for some time with an AFM.  Car starts fine cold and hot, and shows correct very rich on cold start.  It would always go to full rich under firm acceleration.  Now after the engine pull, I barely get mid range AFR and dreaded pinging if I goose it.  Car will slowly rev past 4K so IAT switch seems fine.  Hwy cruise is fine.  Both throttle switches show on/off functionality so I am at a bit of a loss.
Ideas?