RE: Idle Problem
Having the ECU run while the restriction went higher (from the plug) may have re calibrated the fuel curve and confused the ECU a bit. If I understand how Garpar's ECU's work, I think the ECU should correct the problem on its own and re adapt with more run time. Try starting it and let it run through a tank or so, cycling the throttle up and down a few time occasionally, then check the idle consistency again.
Kelly