I guess it really does go to B4.
Car has never run better since replacing the two ECM connectors with Caspers harness splices.
A must if you suspect ecm / wiring issues and no codes are thrown.
Of course in my case the ecm connector got full of water first and threw just about every code there is.
After numerous attempts at cleaning it and reading about the thin tin plating on the connector sockets replacing the ends worked magic.
Time to turn the boost up and take off the snow tires.
Thanks to John S. at Caspers for great products and service.