I posted this on the Boxster forum and have had no replies, so maybe someone with a 996 has had a similar problem. Here is what happened:

A couple of weeks ago we were enjoying a Sunday drive ('03 986 S) on the back roads - 100 degree heat, and the car died on me like it stalled (I was surprised, thought maybe I screwed up and somehow stalled it after driving stick for over 30 years). Checked gauges - temps were fine, etc. I was able to re-start it, CEL was on, and service car light was on, but after a rough idle it smoothed out. I figured I would drive the car home and call for service, but as I eased back onto the road, I found that the throttle was not responding to the inputs on the gas peddle. Shut down and tried again, still no throttle. I was stuck, and had to have the car flat-bedded to the dealer.

Once we got there, the car started up, and the car responded to throttle inputs, and was able to be driven around and parked. Dealer did minor service, could not duplicate or find reason why this happened. Driven it a number of times since without incident.

Now I don't know if or when this will happen again.

Any one else ever experience this?

 

That sounds to me like a fuel pump that is on the way out. What codes were associated with the check engine light? A buck says they were lean or misfire codes because there wasn't enough fuel going to the cylinders.

 

Curious to know what the codes were too.

 

I just had a friend in a n/a 996 that had this happen randomly. turned out to be the y power cable, not sure if yall have those or not.

 

Well I would say to do as a few folks here have said and plug in a OBDII reader, Durametrics or a the Porsche PIWIS if you have a good Indi-Mechanic with the software and see if you have codes. Have you looked at the throttle body itself also? Is it full of gunk.. Some times the throttle body will collect some oil and lag or bind. Could it use a good cleaning? Just easy things to look at first then troubleshoot further.
There are many things to look at from a faulty sensor that's starting to bad E.I. (crack sensor, O2 sensor) to a bad electrical wire, a bad MAF or as 5CHN3LL said it could be a fuel pump on its last leg. Who knows but its best to eliminate the easy stuff first .

 

I had the same problem twice, once in my Corvette, and once with the C4. The Corvette was cruising along happily on a surface street, hiccupped, lost power, and never started again. The C4 lost power; I let it sit for a while, and it fired back up - but it was obviously not getting enough fuel. That was the only time I've had either of my Porsches flat-bedded - and that because I was ignorant at the time of how easy the fuel pump is to access in a C4.