If black smoke comes from the KIA Spectra during the movement, this is due to the overheating of the KIA Spectra engine due to the formation of oversupplied gasoline (overenriched) fuel-air mixture. The operation of the engine in this mode is not desirable because it leads to higher education of the coke in cylinders, insufficient cooling of the engine, as well as explosions of the compound with oxygen in the silencer (because of this and explosions).
The fuel mixture may become enriched for various reasons. Among the most common: incomplete opening of the air pollution (the result of its contamination), the oxygen sensor (lambda-probe) or the engine temperature sensor, the mass air flow sensor and the tp are not available. Computer diagnostics of the car can give a more accurate picture.