iv have aquestion does the iac valve make a car sputter. it runs like its about to cut off unless you give it a little gas

 

The IAC valve controls the air required to allow the engine to idle at the correct RPM. The PCM opens and closes the valve, to maintain the programmed idle speed (800 RPM for an M6). If the valve is not moving, or the air passage is blocked, it could cause the engine to idle so low that it stumbles and stalls.

Put a scanner on it, and observe the IAC "counts". When the idle is below the programmed value, the PCM will increase the "counts" (number of steps the valve opens). If the valve is not working or the air passage is plugged, the PCM will keep increasing the IAC counts, telling the valve to open more. Normally, you might see something in the range os 20-40 counts at closed throttle/0 road speed, If the counts are climbing toward the upper limit of 160, it tells you the IAc valve is not working, or the passage is plugged.

Shoebox has a procedure for checking the windings of the IAC valve:

http://shbox.com/1/iac2.jpg