Any idea why my exhaust would be so dark? It isn't a matter of it smoking, because once it gets a little warm, there is no visible exhaust. It has passed our state emissions testing, but it is leaving dark marks on the garage floor, street, etc.

 

could just be some normal condensation coming from the exhaust.

 

If it will pass emissions, then its probably ok.

 

If it only does it on a cold start, then it is just condensation.