1.4 auto stalling when warm

Hi everyone, my wife has a 1.4 auto and its started stalling when its warm, runs fine, ticks over smooth and restarts straight away just when it comes to a stop the revs drop and it cuts out.
Does anyone have any idea what it can be my wife is learning to drive in it and is really missing it
I would first change the air filter, run the car on petrol/injectors cleaner additive for a while, plug a OBD2 scanner in to port to monitor ecu for starters.:unsure: