I've noticed my Camaro's tailpipes has been smoking all the time lately, at idle it's not too bad but when you press on the gas while in park it'll get really smokey. They smoke when going down the road too, it looks like it's just white smoke but I don't remember it ever doing it all the time. I have replaced the valve seals about 600 miles ago, they were sealed power positive style seals and the car isn't burning any oil. Should I be concerned about this or is it just from the colder weather and humidity? The car has true duals and no cat.