wasap guys..I was hoping that someone here might be able to help me out here.

I got a 89 crx with a d16-z6 motor with a p28 ecu. just recently I had to change the oil ring on my piston. now that I got everything put in. my idle seems to be unstable. it goes up and down from 800 to 1500 rpm. So I tried to check for engine code but the engine light only stay on it never blink. Could it be the ECU or what.