so I started my truck the other day and while it was warming up I noticed that it was blowing nice round smoke rings every few seconds out the tail pipe.. has any one else ever seen this?? should I be worried? the air temp was below freezing by a good bit.. any thought thanks to the wise ones J

 

wow! take pictures! smoke when that cold is normal for a little bit but the smoke rings are coincidental, usually the ebpvalve screws up the ability to get rings as does the length of the piping