Eddy, yes - Knocksense is enabled at 6* IIRC. However, I have an LED on the gauge pod that should light on knock detection and it's never barked at all... so I don't think it's hearing anything. Neither do I. I do have the spark table written to reduce spark lead as boost increases, so there's probably enough retard to cover the issue.

The test drive after changing the filter suggests it was a fuel flow issue..... In "D", the transmission is even holding gears longer now on full throttle acceleration.

It's too early to tell anything about the exhaust, but the engine startes smoother and idles better. I'll know more later today.

Frank