Surge and low idle after tranny swap

I’m getting a low idle after a 2wd do 4wd tranny swap, could it be a low battery? I have no codes…
It’s late I’m gonna screw with it tomorrow
04 3.4 v6 a340f Sas
I haven’t extended the vss line yet,
I’ll check all electrical connections etc.

 

Check your smog monitors... evap, cats etc to see if they are ready or not, if not ready, then the PCM has lost all learned data and you just might have to drive her around to re-learn.

 

Copy will do.
The truck has Been down for a month, one test drive after the Sas, then, just this evening after tranny and t-case install, the battery terminal is shot, new one coming tomorrow.

 

Flagging @gearcruncher to see if he has something to offer. He is a transmission guru.