Quote Originally Posted by Mad Cow View Post
It's best to monitor both banks, much safer that way. Also the latency of the narrowband passthrough might mess with the stock ECU, it'll see one bank responding slower and could try to compensate somehow or throw a code. I didn't notice your wideband controller is made for 4.9, why ask about 4.2 then? I'm really confused.
The wideband cars (at least the 1.8T) uses a Bosch 4.2 sensor. He may have thought that his car was equipped with them.