Originally Posted by
dr.mike
The 30-0300 and 30-0334 use two different protocols.
The 30-0300 uses AEMNet protocol. It can be read by the ProLink CAN inputs. And the data shows up in the AEM section.
The 30-0334 uses OBD2 protocol. It kinda "joins" the group of ECUs ( PCM, TCM, BCM, etc. ) in the vehicle. That's why the data show up as the general SAE air-fuel ratio. The MVPI scanner thinks it is part of the vehicle. The same way it would, if the vehicle had a built-in wideband, from the factory.
I would avoid the serial interface, if possible.
If you want to use the 30-0334 with the ProLink, it needs to be re-flashed back to 30-300 AEMNet protocol.