Cold start
 

I have a 2006 Hawkeye WRX.

When I start it in the morning, been a few cold mornings here recently, it starts fine but does not seem to run that great. It does not cut out but is a bit hesitant to get going. Once the car is warm it is fine but on cold almost seems to be missing a bit.

I am not sure if it is my imagination but sometimes when starting from cold it seems to idle higher (2k) for a bit before dropping down as you drive and runs better but on some occasions it does not seem to idle that high, maybe the car is not recognising that it is cold?

Is this likely to be the coils/plugs or maybe a faulty sensor somewhere?

The car has done 40,000 miles with full dealer history, no real mods apart from panel filter and stainless cat back exhaust.

Appreciate any help.

Coolant Temp Sensor?