1. Do a continuity test on the IAT plug to make sure you are actually plugging in the iat to the correct sensor.
2. Look at your iat, if the tip of it which sits inside your intake manifold is not round then the sensor is shot.
3. Check your injector's resistance using a multi-meter.
4. Install a resistor box the proper way if you need to.
5. Get a good basemap in the car & have it tuned.