97 GM 1500 6.5 turbo

Got troubles and don't know where to start.
under acceleration I am polluting the world with heavy black smoke. At cruising speed, and in town it is normal.
Air cleaner is good, and the Vac reading at the waste gate controller is low. 6" at high idle.
Thinking the waste gate was being left open due to low vacuum I disconnected the line, and the arm drops, so It is working? Then I tried running with the vac line off the controller and plugged and the smoke was even heavier and still lots of power.
I hooked up the vac line again and now I don't know where to look for the next possible spot.
I did some code readings and have these
P0251
0370
0401
1409

I am having trouble finding what these codes mean, and what to do about them.
Any help is appreciated.
The PMD is new, and It does the same thing with another PMD I have as a spare.

Pete

 

Boost sensor goes on these 6.5s quite often ..just a thought its a black rectangular sensor on intake plenum

 

Sounds like the vac pump is all but dead,you need 18+ inches of vacuum at the wastegate actuator and 24 inches + from the vac pump.

Check the vac lines also since the tend to crack and leak a lot.

Wastegate solenoids fail too but some times a shot of WD 40 in the vac ports will help clean and lubricat them.

 

I second that. I just got my diesel and had the same problem. Changed oit my boost sensor and now it doesnt smoke

 

I changed the Vac pump and the truck is like new again. Its got ***** now, not just good power, and no more James bond smoke screen, just a light hint of black if I realy push it.
The idiot light for codes went off too.

When it stops raining I will plug in the scanner and clear any codes that are left and monitor over the next few tanks.
I have 22" vac at the waste gate now with the new pump.