Ive got one data serial gauge in my S14…Its great…you can program the high and low limits so the gauge(s) will automatically switch the display. For example…I use it primaritly for o2, but it will switch to oil temp if it the oil starts to reach you programmed limits. It can be programmed many ways through the AEM with your laptop. I love it. You can monitor your whole car with one of these things as long as the corresponding sensor is hooked to the AEM.
Is it just the gauge or wiring as well?