The engine warning light can indeed come on because ofa fuel or injector problem, in the winter months this is especially true, where in extreme cold the fuel left in the cold engine can become thickened by the cold.
Later while driving, or while moving off, you can then experience a stall, or a severe engine warning (including a juddering of the car).
This is manefest most subtly though by the engine warning light, and the repeated beeping inside the car.
The solution I have found best to this problem is to allow the car to stand for a minute or two before pulling off, without the Air Conditioning running, so as the engine can warm up.
If it occurs while moving along, it is best to pull over with care, and turn the engine off, and wait five minutes.
If you had older 206's you will also have noted that when you put yout key into the ignition and turn to the ready position, not only the dials came online and rose, but there was the loud sound of the fuel pupe working actively from the battery to bring fresh fuel into the engine.
In newer models (2002 onwards) this sound is much quieter, and I believe the task is not as actively performed in the newer cars. Meaning that the fuel pipes in the engine are not flushed with fresh fuel before ignition starts.
My advice in this instance is to take your key totally out of the ignition, count to twenty, and then place the key back in the ignition and move it to ready, only. And repeat this once or twice before turning the car over.
Then sit and allow the car to idle.
If te engine warning and beeping starts straight away, stop the engine again and re-perform the above ritual. But wait five minutes between tries, so as the heat you may have generated in the engine has chance to warm the cold fuel lines causing the problem.
Jon, February 2007