Thanks for all your suggestions but I want to stay with the stock tune. I'm just trying to understand if something is physically wrong, so I can fix it. Maybe a leak or a rattle or something?
The only symptoms I have found are an odd noise just around 3K rpms, like a slight rattle or buzz. Happens as I rev past 3K and as I let off and the rpms drop through 3K. Only happens for second. Maybe I'm hearing the turbo?
I have also noticed that when I sit with Romraider showing the #1 Knock Sensor signal, even stationary at idle, it is flashing a 1 every few seconds. I can't really be knocking at idle (can I?), so something must be showing up as fake knock. Or is that normal?
Other than that, I can't find anything to fix and I'm stuck.