Leaning out when turbo timing

[Deadjai]

So I'm running roughly 14.7 on my wideband at idle and when I take out the key so the turbo timer is going the wideband jumps to like 15.9 or 16+ then I turn the key back to the ignition point without shutting off the car or the turbo timer and it
Goes back to 14.7??? I'm really confused because when it leans out it starts to surge a bit.

Rb25 in to s13
Aem ems for computer
Greddy turbo timer
Voltage is 13.8

Everything is new and this problem just recently happened out of no where any help would be appreciated
I called aem and they were clueless.