TFSI poor throttle response when cold

Hi all

My 2011 vRS petrol suddenly began to run quite poorly when cold. It doesn't misfire and is ok under power, but at low rpm and low load it seems to hunt for want of a better description. I replaced the coil packs and it made little difference, now I'm wondering what to try next - I'm thinking a sensor may be on the blink although an obd scan shows no error codes. Can anyone suggest possible culprits? I'll probably start going through replacing them beginning with the cheapest.

Any suggestions would be much appreciated.

Thanks in advance

Chris