I bought a car off rn marketplace a 2004 mustang which looked good. After my drive home however the ses light popped up and I check the codes it they were p0201, p0205, p0207, and pending codes were p0206, and p0355 ignition coil e. The guy had his base 2004 engine swapped with a 99gt engine he also had the valve cover replaced with further questioning he said the ses light came on after the valve cover replacement but now I can’t get a smog so the cars just sitting till I can get help on how to diagnose and fix it.