Hi all,
I was wondering if anyone has found a solution to getting data from their OBD-I Nissan’s ECU? I don’t want to replace the whole computer with a standalone due to the cost and wiring. I want more data on my r32 skyline but don’t want to have a bunch of extra gauges on the dash and sensors wired in everywhere.

My current idea is to use an Arduino microcontroller to read data from the stock computer, through the OBD port and display it on a screen mounted on the dash somewhere. It could be configured to send signals to ECU just like the Nissan Consult devices. One could then see things like engine temp, voltage, injector pulsewidth, fuel economy, etc while driving. It could also read and clear error codes.

The really cool part is that it would be easy to control outputs like progressive water/methanol injection, boost control, or read an ethanol sensor for a flex fuel setup. The Nistune setup allows you to use ethanol as fuel but you have to convert the sensors frequency signal to a 0-5V signal.

Ultimately the idea is to create a cheaper system of displaying data from the car, in real time, to help with tuning and diagnosis.
I would love any feedback on how you all have solved this, thoughts on this idea, or if any threads already exist.