I think the issue you will run into is you will not be able to set-up the new sensor on the existing Subaru CAN network. You would have to be able to adjust the ECU to not only see the new Oil Pressure sensor on the CAN network, but then also output the data to the OBD port.
I can speak from experience that it is very difficult to get oil pressure and oil temp. into the RaceCapture through the CAN network. We struggled to get a RaceCapture Pro unit to see the sensors coming from a Megasquirt. Once we did get the RaceCapture to see the sensor data through CAN, we could not get the data to make sense, let alone be useable.
We have since abandoned the RaceCapture in favor of an Aim unit, which instantly handled both Oil Pressure and Oil Temp coming from the Megasquirt via CAN data. I am not saying the RaceCapture is a bad unit, we just could not get it to display the data we wanted via CAN, so we moved on to another until.
https://forum.autosportlabs.com/view...hp?f=40&t=6391