Black smoke coming out from my sedan

[skyhawk 0]

For some reason there are instances when my sedan would emit black smoke. I have already checked the engine and found nothing. I don't smell anything bad like fuel leakage or something but I still get instances when my 7-s sedan emits black smoke.

Any ideas?

[copper 0]

Black smoke is usually caused by excess burning of fuel. It is possible that the air filter is clogged.