Look at it this way Ross, if your ears have heard the engine pinging, then the knock sensors heard it long, long before you did. In fact the most damaging type of detonation is the light and inaudible version, because the driver doesn't understand to lift off...they cant hear anything wrong. Thankfully the knock sensor knows all about this 'Delta 1' knock (as some describe it) and takes according remedial action. If you hear detonation in an XR6T engine it can mean a few different things. The first of course is that the knock sensor itself has simply been switched off. This we have convered, and there is really no sane reason for it in a road car. However the engine can still ping if physical conditions are met that the activity of the knock sensor cannot correct. Take my 'hypothetical' example...... A dead standard 'T' running 19psi of boost at 3500rpm, with 22 degrees ignition timing in the map, and a commanded AFR of 14.X:1. Even with the stock 12 degrees of timing the knock sensor can (and will) pull out of the map, the boost is so far 'off the scale', and the mixture so lean, that almost no amount of timing retard will protect the engine from destructive high speed detonation If you can hear detonation at all, then its a fair bet you have bags of low level inaudible pinging as well. My best advice is to seek a professional tuner - and I dont know or care who tuned your car - who understands the very basic fundamentals and physics involved in tuning a modern four stroke engine. Its not magic and guesswork...its science Sounds like a tune an SA guy got from a visiting tuner R U sure it wasn't a tune slipper by the fixer?? <or just a figment of your imagination??