I currently own a 1996 Oldmobile 98 Regency. It just creeped over 230k, and the car is starting to make all sorts of fun for me.

Yesterday coming home I stopped at a gas station, and when I started the car the engine starting revving up and the dashboard would flash to matching the revving of the engine. (When the revving would stop the lights would shut off then reset with all the warning lights blinking. The lights would turn back on right away when the engine started ramping up again.)

I shut the car off, restarted it and I was able to drive home a couple miles with no issue. Now it'* happening every single time and I'm not sure where to start looking.

The day before while I was driving the dashboard blinked and reset with a low coolant/low oil/traction ctrl warning, but there were no issues, and things looked alright when I arrived home to check.

I also changed out my spark plugs the weekend before, but I was unable to get a couple off, and have yet to resolve that issue.

I'd double check connections and look at any wiring that you may have done or disturbed.