I have had a rough idle since I've had the car. Tonight, I drove home from work in 27* weather and it was gone. It was running at normal temp, but the rough idle was gone. Does the frigid weather have something to do with it? When it's warm out it runs like crap.

 

Idle Air Temperature sensor comes to mind.... Maybe something to look at. All Z's love cold air though. Get them up to operating temp and shove cold air in and you'll have a beast

 

That's what I thought, IAT, only it's a new sensor. Thanks.

 

Who else has ideas?