Car starting rough when cold
 

Hey guys just need a little input before i go spend money.
I park the car in our heated garage every night and in the morning no trouble when the car is cold.
When i go to leave work at the end of the day the car seems like it wants to stall after running for about 2 minutes or so. I don't like driving the car when it's cold so i tend to just let it sit there and run for about 10 minutes or so. The car will be reving at 2-2,500 and then all of a sudden drop to about 600 rpms.
I`m thinking that it might be in need of some new coils and plugs but i just wanted to see if anyone else has been having the same problem. It is around -20C here when it seems to act up.

The high idle is due to the really cold temps, the ECU will force a high idle when under a certain temp until it crosses that threshhold and it drops to a normal idle. Stalling at idle could be just about anything, but if it's only trying to stall after this really cold high idle, it's possible that you have a failing O2 sensor that is messing up your fuel trims, and it has trouble adjusting correctly for when it warms up enough to return to a normal idle.

Just a guess there. Its clearly temp related, and most likely what the ECU is doing based on the temp it is seeing.