you can get a controller that will log your afr(usb, sd card, etc) or ouput to a gauge(some do both) that has the option for a narrow band output that can feed your ecu
Most of these don't work well in the 2.7t, they simply do not give signals the ECU expects.
or just weld another bung in place and add a second sensor.
The most common solution. Also, there are several threads on NEF about wiring those into unused ECU inputs for logging.
