Black smoke

[Powerstroke127]

K stupid question but gotta ask. K does exhaust, straight pipe or what cause all that black smoke to come out the exhasut

 

[little luke]

To much fuel and not enough air. Exhaust alone won't give you an issue with smoke. Why?

 

[Big Angry Hillbilly]

Mechanically it's insufficient air to complete combustion. Can be over fueling, sticking turbo, plugged air filter, etc.

 

[dirtboy25]

A straight pipe wont do much for black smoke but if someone were to put dual stacks on a truck it will smoke like a freight train. Usually the taller they are the more smoke comes out.

In all seriousness though, the two guys above are correct. Too much fuel, not enough air. If you have black smoke you will need either a bigger/quicker turbo, or better tuning.