knock sensor question
 

Where exactly is the knock sensor on a 86 S/4? . . . What happens if it doesn't work?

IIRC no S4 cars had knock sensors. Only the S5 turbo cars got knock sensors. Even if I'm wrong on the S4 turbo cars, none of the 2nd Gen. n/a cars had knock sensors.

yep, just the turbo cars have them