2.7 TDI: Rough Idle, Engine Misfire?

Hi, I've been having the following problem since Saturday.

I was driving on the highway at approximately 220 km/h when suddenly, the accelerator stopped working.
I then let it idle until the exit, and there I noticed that it was running extremely erratically. In the engine compartment, in the area of the throttle body, everything was oily.
We took the throttle body apart, cleaned it with brake cleaner, and reinstalled it. When the engine is idling, it runs unevenly, but when you press the accelerator, it recovers.
The hoses under the throttle body were completely dry, with no oil present. It seems like the throttle body might have stuck open, or something caused it to do so.
There is no visible dripping or spraying of oil anywhere, so it's impossible to determine the source.

However, the servo oil reservoir is also located in that area.

The error memory was read, and the following errors were stored:

Sunday, July 15, 2012, 7:52:52 PM: 36381
VCDS Version: DRV 11.11.1
Data as of: 20120106.


Address 01: Engine Control Unit (ECU)
Label file: DRV\059-910-401-BPP.lbl
Control unit part number: 8E2 910 401 P, Hardware: 8E0 907 401.
Component and/or version: 2.7L V6 TDI G001SG 0030.
Encoding: 0011921
Company number: WSC 31313 141 107072
VCID: 2E6B216FB90C659
3 error codes found:

000305 - Bank 1, Probe 1.
P0131 - 001 - Voltage too low - Intermittent.
Freeze Frame:
Error status: 00100001.
Error priority: 0.
Error frequency: 1.
Mileage: 137,647 km
Time: 0.

Freeze Frame:
Speed: 3612 RPM.
Torque: 487.5 Nm
Speed: 207.2 km/h
Duty cycle: 100.6%
Air mass/Hub: 904.8 mg/H.
(no unit): 0.60
(unit): 0.0

009253 - Valve for cooling exhaust gas recirculation.
P2425 - 001 - Interruption - Sporadic.
Freeze Frame:
Error status: 00100001.
Error priority: 0.
Error frequency: 1.
Mileage: 137,663 km
Time: 0.

Freeze Frame:
Speed: 0 RPM.
Torque: 0.0 Nm
Speed: 0.0 km/h
Key ratio: 1.0%.
Voltage: 12.01 V
(unit): 0.0
Temperature: 829.4°C

005663 - Spark plug, cylinder 6 (Q15)
P161F - 001 - Interruption.
Freeze Frame:
Error status: 01110001
Error priority: 0.
Error frequency: 1.
Mileage: 137,669 km
Time: 0.

Freeze Frame:
Speed: 840 RPM.
Torque: 117.0 Nm
Speed: 0.0 km/h
Key ratio: 1.0%.
Voltage: 14.29 V
Touch ratio: 23.3%
Temperature: 16.2°C


Readiness: 0 0 0 0 0

Best regards,
René