good or bad to have knock sensor

i was wondering what the advantages and disadvantages were to having a knock sensor or not having one...thanks

if it works, the ecm will tailor the spark programme to give maximum advance, if it does not work then it will run in 'limp home' mode and power will be down, emmissions will be up....dogs and cats living together, 4 horsemen of the apocalypse - u name it.

With a knock sensor, if your engine starts getting detonation/preignition, the KS will retard your ignition timing to try to eliminate the pinging. This will lower your power slightly, but it's better than allowing the detonation to continue, which will damage your engine.

If you're racing, disconnect it. For daily driving, it's good to have.