I have been having the same sort of problem with my new Panda Easy. you can see my posts regarding this on the forum under 'New Yesterday' in the Panda section. I have now done just over 1000 miles in it, it is very easy to stall, very slow to pick up in the 1000 to 2500 rev range, occasionally when picking up there are two surges of power. City driving is a real pain, other vehicles have left us behind before it will pick up. Getting onto roundabouts and pulling out of junctions is a bit like Russian roulette. On hill starts, when you can get the car to pull away the engine is very flat.
Some other Pandas seem to be having the same problem, it has been back to the dealer a couple of times, the ECU software has been updated, with no apparent improvement. We contacted Customer Services and I have be told over the phone that this is a known problem and they are trying to develop a software fix. I have asked them to put this in writing. They said that anyone experiencing a problem should go to their dealer and make sure that it has been logged with Fiat. My daughter now has my old Panda which has always run extremely well, uses less petrol and is like a racing car compared to our new one. It would be great if it turned out to be a simple problem such as you have had, but I would have thought that if the engine was sucking air there would be other problems as well.
Could you add a post to my thread please?
David
David