What's up everyone. So I have a 2016 focus ST. Currently has 29,5xx miles. Have been bringing to dealer for weeks with issues involving the 4th cylinder misfiring. Car has a borla cat back exhaust, had a Cobb stage 1 accessport and a K&N cold air. The engine apparently is totally shot I ask Ford what exactly is wrong and they just say I need a new engine and I voided warranty. Can anyone please offer any insight or help? Has anyone else experienced similar issues?