Ducks964

Does anyone know which of the 3 wires provides the signal to the DME? Looking into using a PLX air/fuel gauge and it has ability to provide a wideband signal for the gauge as well as a narrowband signal for the motronic. This way I am hopeful to avoid 2 O2 sensors especially since it does look there is a good place to mount the 2nd one. The gauge is pre-TPC SC install work.

Thanks,
Duck