In my elongated history of living with knock I have wondered about the frequency of false readings from the Knock Link Meter I have. How do I know if it is accurate--a quick red flash is usually not accompanied by my sensation of the car pulling timing (I can feel it during WOT sometimes). But the ECU knock sensor is only functional below 4K RPM, right?

How big an event is a quick red flash--say for instance if I am shifting, occassionally this willing happen if I am doing a 1/4 mile or trying to out run the cops (hehe--kidding)?

I have never heard pinging or detonation. Significant detonation produces the 600 hz vibration that is detected as pinging, right?

Is the location on the left hand side of the top of the block better or worse than the location for the stock knock sensor in terms of accuracy in knock detection?

ECU knock sensor active below 5500RPM, not 4000.

I don't have all the answers to your question, Modaholic, but I definitely can hear knock with my own ears even when it only comes on at green... I definitely hear "bb"s when it flashes yellow or red. Note that I did set the sensitivity of my knock-link to maximum. The knock sensor I use is a Bosch knock sensor. Maybe you have an over-sensitive sensor?

Detonation is around 6400Hz, not 600Hz. The bits of knock while shifting (aka shift-knock) are common, you need to reduce timing in your lower load zones at higher RPMs to get rid of it.

Just because you can't feel the ECU pull timing doesn't mean that it didn't. A plot of the KC values around the knock event will probably show them.