See smoke in headlights behind me

[Mudflap77]

Are you sure it is smoke?
Since having emissions issues on my 2350 and exhaust clamps on and off multiple times I have had 2 of them come loose occasionally.
If the clamps on the elbow between the decomp tube and the SCR come loose and leak you will get what my best guess is steam from the DEF evaporating instead of going through the SCR. If you can stop safely when it's doing this and jump out to determine what it smells like. If it stinks then you actually have smoke. If it doesn't really stink but kind of has like dusty smell or texture (sorry I can't think of the right way to describe it) it's DEF. Start checking your clamps and the end of the exhaust pipe. If you find a grayish dust at the end of your exhaust check your decomp tube and doser for urea build up.