Engine Sputtering -- Need Advice Asap

[myeboxsters]

I have a 2001 Boxster S, 46K miles, 6-speed.

This morning, I went for coffee (about two blocks away) and on the return home, while waiting to make a left turn, the idle suddenly got rough and the car was sputtering. As I made the left turn, the check engine light started flashing, and then it came on full when I entered my condo complex. I limped it around to my outside parking space and shut it down.

A few minutes later, I started it up again. The check engine light went out and it idled normally. However, I noticed that whenever I tapped the gas I could hear a sucking sound from the driver's side. Never paid attention to that before. Not sure if it's normal intake. The sucking air sound only lasts a second, when I first blip the throttle.

Any thoughts on what happened?