Any black smoke at all under WOT?
Chances are it's either a clogged EPB tube/sensor
or your turbo is sticking
With that low of miles on an 06, my guess is it does a lot of sitting around. There are two things that are really bad for these turbos, sitting around doing nothing, and long idle/slow driving.
Turbo is probably just sticking and needs a good cleaning DTS Articles - Turbocharger Reconditioning