I have a 2022 with the full Kooks headers with green cats and x-pipe and am getting a CEL even after trying a bunch of different spacer configurations. With no spacers, I would get cat inefficiency after 100-200 miles but none of the spacers I’ve tried (Fabspeed with mini cats, J style with inserts, or super short straight spacer) can get the car to think the sensors are still functional as they throw low voltage/stuck lean codes pretty quickly.
The Kooks sound phenomenal and seem to make at least a little power, but the CEL’s are unfortunate and I don't want to tune and lose my warranty.
Just a data point for anyone else interested.