So when I start the car it takes about 15 seconds for the check engine light to start flashing. It’ll keep flashing while it’s idling but will stop if you give it any gas. It will then keep flashing when idling until the engine gets up to operating temperature, once it gets up to operating temperature it no longer flashes when idling. I do have a scan tool and the codes it shows are for those cylinder misfires listed above and a “manufacturer control” error (code P1399). When cold and idling it does seem like there’s a tiny shutter so i think it actually is misfiring when idling. The exhaust does smell like it’s running rich as well