Knock Sensor going bad again?

[MudFrog]

Ok, I replaced my knock sensor last year and it fixed the issue I was having at the time. Well now here it started again yesterday, the exact same problem. How do I test the knock sensor? It's to expensive to replace if I don't know it's the problem.

 

[dyeager535]

One of the factory tests is to hook up a scanner, and tap the block near it with a hammer. Watch for knock counts to increase.