knock sensor failure

[Konstantin Bogach]

Robert,
I had a knock sensor on 200tq MC2 turning on "check engine" light.   
Replacing by used one solved the problem.   Unfortunately,  I did not 
have a oscilloscope to check the sensor or experiment with it.   I don't 
remember whether I pulled "bad knock sensor" code but I guess I did.  
Because how could I figure out that it is bad knock sensor?  I am not 
that smart.   Hm...  Maybe I am...  I wish I could prove it but, sorry,  
I don't remember.

Konstantin.