I don't remember seeing this mentioned anywhere. If engine detected knock and pulled back timing, then I installed the knock led, would the led light up? Or would I have to reset the ECU and see what happens? Right now it does normal lighting operations and goes off once car is running.

It only lights up when it detects knock and closes the boost solenoid. It should flash, not remain solid unless there is a serious problem. It will not remain lit if the car is running properly.

I.E. 5500 RPM it detects knock, ECU starts opening and closing the boost solenoid to bring the boost down to about 9psi
(it doesn't close and stay closed, it would cause a real jerk in the driving that you would feel so it pulses instead)
After you shift or bring the rpms down it stops controlling the boost solenoid to give you full boost again.

As long as it lights up when you turn on and off your car it's working fine.

OK thanks. Actually, I'm using a Hallman so no pulling back of boost here. I guess I have to find another culprit as to why my slow ass car is such a dog, or should I say turtle. BTW, didn't see you or Scot at Cayuga on Sat. Man,it was empty. Got in 25run in 5hrs. Maybe that was the problem, no cool down period.

Scott's O2 sensor wasn't working and I never intended to race my car less than 12 hours after my new clutch went in.

We put the knock led in Scotts car on Sat. too and he's getting some pretty bad knock at 5000 rpm and we couldn't deal with it through the AFC or timing.

Time to check the cam timing......

Too far to go when you know a car isn't running at it's peak.