my 07 dodge ram 2500 is the first diesil rig i have owned. there is an older discussion board about carbon build up in the turbo setting the check engine light off. seems long idles and low speed driving is causing the problem. seeing how this is my first diesil i understood that this is why they switched to the ultra low sulfer. to get rid of all the soot, and to help with emmisions?

 

Do you have the 5.9 or the 6.7? The 6.7 w/ DPF is the one you are referring to I think. The VGT turbo would carbon up and could not change pitch and the ULSD is needed so the DPF does not plug up prematurely.

 

ULSD doesn't effect sooting -it's to prevent damage to the new emissions exhaust parts.

The active EGR has caused quite a few carbon-loading problems.