Under my air cleaner housing on my 1.0 l 99 polo i found a small black thin pipe or tube that leads to no where? On the other side it has the same but it is connected to the thing that the air intake hose connects to,

I dont know wether this relates to the problem but my engine revs itself slightly while idle in and around 10000 rpm, i alsohave trouble with my car threatening to stall when im at full lock. Hope you can help.
Conor.