It's times like these when I really miss DSMLink. It would turn on the CEL if the ECU detected knock counts beyond a user-specified amount (and turned off the CEL when the counts dropped below that amount). Using ECUFlash alone, this may not even be physically possible, but it was certainly a fantastic feature to have on DSMLink.

 

more info on knock link plz~

 

Same here, it works really well. I pulled mine apart and flush-mounted mine from behind right above the gauge cluster. Just drilled holes for the LEDs to poke through. You can't tell it's there unless it lights up.