The other day I was driving and started to notice a tap from the engine and car running rough. I got home and scanned it and have a p0300 and a p0306. The misfire counter on cylinder 6 is bad with residual misfires on cylinder 4 and 5 as well but not too bad. I have replaced the plugs, swapped coils and injectors, replaced fuel dampers, replaced valve cover gaskets as well as the lower and upper intake gaskets. I have ran a gas treatment through incase it was bad gas and also did an oil change with ester oil. Also have cleaned the mass airflow sensors and throttle bodies but I am still getting a bad misfire from cylinder 6 that even causes the CEL to flash. I am going to be doing a compression test on it this weekend to test that but does anyone else have any ideas what it may be? It's a 2012 G37x with 104k on it. Any help would be appreciated. Thank you.