Jumping from 1000 to 1700 continuously? Your car's idle should be 700-800. Sounds like too much air is getting past the throttle body, through the IACV. Check for an idle adjustment screw on your throttle body. If you have one, turn it clockwise to stop the erratic idle. Cranking it all the way down should almost stall the vehicle due to not enough air. Then back it off until the idle is correct. Reset the ECU after doing this, but remember your Radio code and presets.

J