I found this on another forum. I found it helpful.
LBZ Turbo Vane Position Sensor Replacement
I recently had the vane position sensor go out on my 07. The symptoms were that there was hardly any boost between 1500-2500 RPM's. once you hit over 2500 RPM's it seemed to get full boost instantly. Another symptom was at idle, the vanes in the turbo would open and close all the time... This made it sound like engine would gain RPM's and then idle back down.
For an LBZ Duramax there are 3 options for vane position sensors:
1. GM# 98011739 - Vane Position Sensor for LBZ Duramax
2. GM# 98061570 - Vane Position Sensor for LMM Duramax
3. GM# 12635324 - Vane Position Sensor, Supersedes LBZ and LMM #'s
The prices vary for each of the parts:
1. GM# 98011739 - $230 up to $389
2. GM# 98061570 - $211 up to $357
3. GM# 12635324 - $400 up to $506
(These prices are from different online GM parts distributors and local dealers)
Currently GM# 98011739 (LBZ) is no longer available. As of late Oct- early Nov 09, GM# 12635324 (New Part #) is not yet available for sale. It is waiting to be approved by GM for the sale of that part.
I used GM# 98061570 (LMM) because it was available and cheaper than the new release part.
Removal of old Sensor:
1. Remove resonator from the top of the intake
2. Follow wire out of the top of the turbo down to the drivers side of the block
3. Unplug the sensor
4. Using a 1" Crows Foot, a 3/8" ratchet, and 6" extension; loosen and take out the sensor
Installation of new sensor:
1. Using a 1" Crows Foot, a 3/8" ratchet, and 6" extension; tighten sensor to 21.5-24.9 N.M of torque (15-18 Ft. Lbs)
2. Run wire down to the plug on the drivers side (place in a safe route so that the wire will not be harmed)
3. Plug sensor in
4. Re-install resonator on the intake
5. Start the vehicle and check to make sure everything is in working order