I would help if you stated the year. Also, in the USA the 2.0 liter four-cylinder was never available, so I assume you have a model for another market. Details would help.

I had a similar idle issue with my KE system a few year ago. It turned out to the throttle position switch that tells the system the throttle is at idle or WOT. On my 2.6 there's a three pin connecter above the inlet manifold that makes it easy to test the switch.

It's difficult to access for removal, so I just thoroughly doused it with electrical contact cleaner and it gained full function.

Duke