Black smoke is mainly a sign of overfueling. I would investigate the FPR (replace it), and possibly get the injectors checked as well.
Its possible some debris jammed the injector open for a split second and thus caused the engine to overfuel on one cylinder causing what appears to be a missfire.
So:
Fuel filter - Just in case its not stopping crap from the tank
FPR - If its bleeding, or not within manufacturered limits it could be causing the car to overfuel.
Injectors - If it continues.
Some fuel treatment would be worthwhile in the meantime.