engine stall

Check for vacuum leaks first. Don't even read for codes until you do this.

Vacuum leaks will sometimes set codes such as oxygen sensors, idle air control valves, throttle position sensors, misfiring, and just about anything you can think of. This is because all of these sensors depend on a good, steady vacuum.

Once you've eliminated all vacuum problems, read for codes. Look for patterns. For instance, if you get a code for all four o2 sensors, then it's probably false. Rarely do all 4 o2 sensors go bad at the same time.

You can check the Mass airflow sensor (which could be causing the problem) by idling the engine and tapping on it with the handle of a screwdriver. If the car acts up, then it is probably bad.

You can check the idle air control valve by removing it and looking for excessive carbon build-up. If so, you can't clean it - you have to replace it.

There are many possible causes, but these will narrow it down some.