Check Engine Light on Q7 3.0 TDI

I got the following 2 fault codes on my Audi Q7 3.0 TDI. Any idea where to start?

008430 - SCR NOx Catalyst Bank 1
P20EE - 001 - Efficiency too Low - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 140635 km
Time Indication: 0
Date: 2013.10.14
Time: 16:35:41

Freeze Frame:
RPM: 1806 /min
Speed: 72.8 km/h
Voltage: 14.36 V
Temperature: 252.0°C
(no units): 0.01
(no units): 0.32
(no units): 0.80

012558 - Bypass Valve for EGR Cooler 2
P310E - 000 - Implausible Signal - MIL ON
Freeze Frame:
Fault Status: 11100000
Fault Priority: 2
Fault Frequency: 3
Reset counter: 255
Mileage: 141542 km
Time Indication: 0
Date: 2013.10.24
Time: 20:12:27

Freeze Frame:
RPM: 2142 /min
Speed: 108.6 km/h
Inj. Quantity: 21.0 mg/str
Temperature: 466.1°C
Temperature: 230.1°C
Duty Cycle: 83.6 %
(no units): 36.0