I hooked up my OBD-II scanner and noted that I still get RPM signal/indication but tach gauge does not work. Does the ECU get the tach signal from the same component as the tach? I don't have the wire diagram at the moment to trace it out myself.
Thanx

 

As it turns out, it was the Ignition Control Module(ICM) on it's way out.

On way to the house the car stumbled and quit at stops three times. At the house it initially would idle fine, but then stumbled when I pressed the accelerator. Then as I was looking into the issue it quit completely and wouldn't start.
After some troubleshooting I narrowed it down to no spark. Since wifey's '99 LX was sitting right there, I did some part-swapping instead of proper testing, and found the ICM failed. I put in a new ICM, car started fine and tach works normal.