I've had the k&n sri on my si for about 3 months now. No CEL ever. Just make sure when you install it everything is tightened down to prevent leaks and disconnect the negative battery terminal to reset the ECU and let it idle for 15 minutes before driving. That way, it will adjust faster to the increased air flow.
On a side note, the only abnormality you might see with an sri is idle fluctuation without a tune. Mine will bounce around from 800rpm to 1100rpm if I shift into neutral and coast while driving. It returns to normal at a stop, though.
As always with an sri, beware of heat soak if you live in a high humidity, hot climate. I personally have not noticed it much as the weather isnt hot yet, but its something to think about.