I just finished up my install recently. A few pointers, calibrate your sensors, move IAT sensor, set crank reference angle and make sure MAP has signal. I had some trouble getting mine to fire initially due to a bad map. It all worked out, now I'm working on the tune.
Actually, you can power it up with the iac unplugged. Just don't plug it in or unplug the iac with the ecu powered up. Lots of race cars don't use an iac at all without damaging the box