Engine rough, noise and black smoke through exhaust

[alberfb88]

Hey guys. So a few weeks ago coming on the motorway everything was ok. Then I stopped at a red light and car started sounding like a tractor in the engine area.
Havent used it since then. Today I went to start it to try and find out what it is and after the car warmed up black smoke would come out of the exhaust, idle is a bit rough as well. Any thoughts?
Leon cupra r mk1 with custom made exhaust is the car. Thanks buddys