Colin_T - we did the 4th March 2024 Trackday (three days ago) in our R500 Duratec - we initially failed the Static Noise Test, but after re-installing the Catalytic Converter we passed at 101db (the maximum limit) @ 5,500rpm. We were also concerned about the low Drive-By 87.5db limit but even at full chat we didn’t get any Warnings. I hope this helps?