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

[Mr2Mike]

Over-fuelling could be down to the MAF and/or exhaust oxygen sensors. Have you checked to see if any diagnostic codes are stored?

[Robatr0n]

Have you checked to see if all your boost hoses are still firmly attached?

[227bhp]

What kind of tractor did it sound like?