weird intermittent

I have a 06 scion tc that bucks and surges at all speeds in closed loop ,unplug 02 runs pretty decent ,I found I momentarilly lose my 12 v reference even with 02 unplugged,maf,purge,efi relay,,downstream o2,and ip,all have this same power source , anyone seen issues with this , so far have had maf ,purge and downstream o2 unplugged still lose voltage