I'm doing a Jspec TII swap in my 91 coupe. I am done after I connect all the vacuum hoses. But I was told that I need a knock sensor for my S5 TII engine? I thought that the S5 TII's knock sensor was controlled in the ECU. Please help me out, I don't want to buy it if I don't need it. Thanks in advance.

 

Not sure but I think I remember reading the stock knock sensor doesnt do too much for sensing knock except at or near idle.

 

Unless it's been removed, it's screwed into the front rotor housing above the trailing spark plug.

The ECU doesn't control the knock sensor, it takes info from it. The engine will run fine without it, but you'll have a bit less protection from detonation.

If you're using the TII ECU and harness, then it'll all just plug straight in. If you're not, why not?