Just as the title of the thread says - I'm running a '99 GTP with 210k which (had) zero degrees of KR at WOT until I built and installed an open cone intake. After that, I got 2-4 degrees at WOT above ~4k, which was not solved by installing a downpipe. Adding a bottle of 104+ octane booster didn't do anything to reduce KR, either.
No DTC's except for P0140 (rear O2 sensor that I pulled when installing the downpipe), and I just put in new spark plugs and wires.
Video: Accelerating up the onramp - YouTube
The gizmo up front is a Linear Logic scangauge which is showing (on the right side) AFR and KR.
I guess I should be asking if this is false knock? I'm really itching to do a pulley drop.