tighten exhaust up at the heads. if its popping you may have air getting sucked into the pipes and throwing the readings off on the 02 sensors, hense low voltage or lean codes. also you should replace the ex.port gaskets when intalling new pipes.
It was great finding this code diagnostics page greatly appreciated. Is the code po563 the same for 2006 softtall heritage classic and if so (P0563 Battery Voltage High) is this a serious problem? thank jim