Exhaust emissions warning light

Hi Guys,

Hoping for some help.

Had the exhaust emissions warning light come on. Run a VAG-COM scan and got the following faults.

3 Faults found:
17704- Error in Mapped Cooling System
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
17608- Boost Pressure Control Valve (N249): Mechanical Malfunction

Also,

01039 - Coolant Temperature Sensor (G2)
30-10 - Open or Short to B+ - Intermittent


I have little mechanical knowledge so I don't know if the faults are related or what the causes could be? The car appears to be driving absolutely fine.

Any idea on what it will cost to fix whatever is causing these faults?

Thanks for any help you can give.