What cause black fluid exhaust?

Black fluid exhaust is typically caused by incomplete combustion of fuel, leading to the production of soot and carbon particles. This can occur due to several factors, including a rich fuel mixture, malfunctioning fuel injectors, a clogged air filter, or issues with the engine's ignition system. In diesel engines, it may also result from excessive fuel delivery or poor quality fuel. Regular maintenance and timely diagnostics can help prevent this issue.