1.6tdi Rough cold running

Hi … after selling my petrol VRS for a cheaper running diesel ( think I made a mistake) I’ve had trouble free nearly 2 years motoring…. Last month on a frosty morning my 1.6tdi 17 plate Octavia started ok but seamed to be running rough as though in 3 cylinders… there was no excessive smoke and when warmed up 10 mins she ran fine …. I checked the glow plugs with a low resistance meter and got a reading off all but No3…. This has the pressure sensor on it which has now been changed……The only fault  thrown up on the Diagnostic was airflow temperature sensor?? Can this cause these problems as the car is still the same …thanks