Bad Knock Sensor (p0326)

[LeJ]

I've had an engine light go off with this code twice now, both time I had to clear it myself. On Sunday it came back on, which I wasn't suprised, but after leaving work today the engine light turned off and the code cleared itself.

I was under the impression that this code doesn't clear itself? Can anyone expand on this, I've had the car checked out, everything is good, just a bad sensor that I'm replacing soon, but how did it clear itself?

Thanks,

David