Maybe this question is already on here, I couldn't find it. This relates to my first question a couple days ago... What the hell is the function of a knock sensor, anyway?

 

It senses detonation and retards the timing so as to not damage the motor. Basically is feels when the motor is not running smoothly and adjust the timing to smooth it out.

 

Modern engines try to run the engine with the timing as far advanced as possible. Under some conditions, this will result in detonation (ping or knock) which is damaging to the engine. The knock sensor creates an electrical signal to the ECU when it vibrates at the frequency of a knock. The ECU is programmed to retard the timing a few degrees until the knock stops.

When I swapped EFI onto my Chev V8, I had to mount a knock sensor on the engine.

 

Cool. Thanks guys!