Hey guys Im pretty new to the forums, i did some lurking but never really made an account. Any way last night while i was driving I blew a coupling off and there was a lot of black smoke coming out of the exhaust. I put the coupling back on and pressed the gas in neutral to see if i fixed the problem. I turned my car off and as i was walking to the back i noticed a large amount of black powderish stuff on the ground next to my exhaust. It looked like dirt was launched out of my exhaust. I just recently bought the car should i be worried?

Im guessing its carbon build up

 

I would've guessed the same. you probably just got some build up in there, and then blew it out.