There's a TSB for "Warm ambent cold start stumble." I.e., if it's warm
outside and your car's been sitting awhile, it'll hesitate badly for about
20 seconds. After that, fine. There's a reprogram available to fix this.
But I've never seen this cause the car to stall, so there may be other
issues. A stuck open purge valve could cause this, as could a leaky fuel
injector, but there are a number of plausible causes. I'd recommend
taking it to the dealer and leaving it overnight for them to start in the
morning. After they've repaired it, ask them to keep it overnight again
to check and make sure everything is fixed prior to returning it to you.