2006 Kia Optima

Hey guys i have a 2006 kia optima, and when idling for about 3-4 minutes white smoke starts to come out my tail pipe, or when im idling at a red light, but the car isnt over heating or losing any coolant. Does anyone think they might know what it is?

Any check engine lights or drive ability problems?

How long of trips/drives are you taking ?

After driving for 1/2 hour or more, does it still have the white smoke?

Yes the check engine light is on, i got a code for a O2 sensor may that be the problem?