Engine idles rough and check engine light flashes

Scan the vehicle for trouble codes. There will be a P0300 for a random misfire and usually will set another code indicating which cylinder it is for example P0301 for cylinder number one misfire. If you have a P0300 and say P0301, P0302, P0303,P0304 then I would I would check the valve adjustment. The adjustment should be done when the engine is cold. What I have found that the exhaust valves eventually get too tight. And given the mileage you have on the vehicle, most likely it has not been done or it has been a very long time since it was done?

So for now, start with the code scan and let us know what codes you pull to be able to point you on a better direction. If you have a scanner here is a link to help you do the procedure.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Nice work JIS001!