Here it is truck bucks going down the road and at lights when taking off it blows black smoke then white smoke I cleaned Egr valve I dont have gauges to see what boost is doing. But i get no codes Could it be the ICP other then that the truck runs great. It dosent do this all the time just perotic. any help thanks

 

My 2004 6.0 had a bucking problem but I did not have the smoke issue you have. We traced my problem to an EBP sensor. (Exhaust back pressure) Once that was changed the problem was gone.

 

The ICP is a common failure item and it can cause bucking when it fails. The EBP can do it also as wildcat421 said, but it fails less frequently. Can you see if it has thrown any codes?

 

you can disconnect the ebp wich is easy to get to and see if the issue goes away.
you can also disconnect the icp and see if the issue goes away.
Do you have an early or late build engine?

 

Was your truck doing this bucking thing around 45 mph up to 70 mph. mine does it in 5th gear or overdrive per say . kick down on it and gets up and goes.