tune saved?
 

My battery died in the Z, I understand the tune is saved on the ECU, Stillen supercharged. When I finally got her started again let her run for a bit. Then took her for a drive and noticed under boost I lean out.

So, does the ECU need to relearn the perimeters again or should I take her to my tuner?

I've had mine without the battery for a couple days and mine didn't go lean when it was hooked back up.

It should not change, it might just be the car doing some minor adjustments since it did reset.
Keep an eye on it, and if it continues maybe do some data logs and send to your tuner to review.

I think I'm going to schedule an appt and see what is going on