filter changed but still black smoke coming out of exhaust

[sanstev]

there was black smoke coming out of my exhaust and one of my friend suggested that i should get all the filters changed which i did but i am still facing the same issue

now what should i be doing to stop this

thanks

[trueguy]

Black smoke means unburnt fuel, and its major causes are as follows:

Black smoke is caused when the mix of fuel and air becomes un-balanced. Normal mixture is 14.5 parts air to1 part fuel. When the fuel to air mixtures change because of a malfunction the mixture can go as high as 14.5 to 2 or 3, two to three times the proper amount. The black smoke is the excess fuel generated from the rich mixture and can be cause by one of the following:

* Plugged Air Filter

* Shorted or stuck fuel injector

* Failed fuel pressure regulator

* Vacuum leak

* Shorted PCM Sensor