I don't know if you would get a CEL from not having the IAB hooked up. Just disconnect it now and drive around for a while (yeah, performance will be a little out of whack, but shouldn't cause any harm) and see what happens. If you get a CEL, then plug it back in and reset your ECU to clear the code.
If it does give a CEL, you can probably trick the ECU by putting a resistor in place of it. Just use a multimeter to measure the IAB solenoid resistance -- then get an equivalent resistor (make sure it can handle the necessary power level of course).
Disclaimer: This is not from experience, but rather an educated guess.
If it does give a CEL, you can probably trick the ECU by putting a resistor in place of it. Just use a multimeter to measure the IAB solenoid resistance -- then get an equivalent resistor (make sure it can handle the necessary power level of course).
Disclaimer: This is not from experience, but rather an educated guess.