Okay, I think I have an issue with false knock. Here's the details: The car was tuned elsewhere and I noticed that the tuner rather aggressively turned down the various knock parameters. (Probably because of this.) However, it looked to me like it was too much so I figured I'd set things back to stock and see for myself. After I saw the consistent knock, I put the stock timing tables back in and pulled 2 to 6* to see if it would go away. Well, if you look at the attached graph, it didn't.
So, what are my options?
1) I know to check the exhaust, but I have already done this because it was making contact with the car constantly. It doesn't do that anymore but I will check it again.
2) Replace the knock sensor. Well, I suppose I can but do I really have an indication of failure or am I just replacing parts and hoping? Are there other mechanical issues to check? As far as I can tell the headers are not hitting anything.
3) Make the knock parameters less sensitive. What would be good choices without causing the car to ignore real knock, if any? I don't mind if it occasionally pulls a little timing, but right now it's way too much.
Thanks ahead of time.