2001 SS ocassionally won't start/stalls while driving
 

:( No check engine light comes on and no code. My mechanic changed O2 sensor, it worked fine for 3 days and and had the same issues.

Oxygen sensor WILL NOT cause no start or a stall. What scan tool is he using? May be codes, just none a cheap tool can pull. My bet would be on a crank sensor. That's assuming you have fuel pressure.

I agree, crank sensor is likely. I've seen it be fuel pressure related, ignition related, and MAF related.

Nitehawk and Aussie, I apologize. The crank sensor was replaced also.

Unplug the MAF when it happens. See if it starts. You could try cleaning your MAF. Check the ground on the ICM harness (It is on one of the studs underneath the ICM bracket). Failing ICM will do this also. Check the fuel pressure.

Bring the car to Autozone, they will scan it and tell you the codes, if there are any stored.

Where is the part from?