I have an audi TT quattro 2000 and I can't drive it because it won't last two blocks before it starts heating. I scanned for codes and some things came up:

VAG codes :
16684, 16685, 16686, 16687, 16688 : Cylinder 1-4 "misfire detected" This is everyone of them
17966 : "Throttle actuator electrical malfunction"
18010 : "power supply (b+) Terminal 30 low voltage"
17967: "idle speed control throttle pos. Adaptation malfunction"
17972: "idle speed control throttle pos. low voltage during adaptation"
16891 "idle control system higher than expected"

Does anyone know what it could be and if my problem is directly related to this?

 

Blown head gasket?

Start with the simple stuff. How much coolant is there in the radiator? if it's empty fill that thing up quick!

 

I had the same problem with my '02 Roadster. Mine turned out to be a combo of things. Most importantly the plastic impeller on the water pump was cracked and nonfunctional. There were some other issues with the electric cooling fans as well. I recommend looking into the water pump and changing the timing belt while you are at it if it hasn't been done.