Q&A

 Master

It could be many things, unfortunately and without experiencing the problem first hand or being able to do some basic diagnostic tests its hard to say. Your car has On Board Diagnostics (OBD2). A 16 pin diagnostic socket under the dash allows a scan tool to be attached to interrogate the on board computer in your car. A professional grade scan tool reads stored trouble codes, pending trouble codes, looks at live sensor data so you can look at a sensors performance and output signals without having to do intensive testing at each sensor, (cheaper scan tools have limited capabilities and may only read the trouble code stored). As with most things automotive it's best to check the basics first, check for vacuum leaks, fuel pressure and delivery volume. Verify engine mechanical integrity before looking for complex problems check that the basics are sound.
Could be a bad throttle position switch, failing ignition, vacuum leak or false reading from the airflow meter/MAF/MAP sensor.