I think I remember you just getting this car. How did the oil look when you first changed it? Does it look okay now? How is oil pressure? Still not throwing any codes? Any extra smoke or liquid from the exhaust? Have you let the car idle long enough to warm up and get the coolant flowing again? Even compression in all cylinders? Plugs all firing? Did the car shudder and jump when you gave it gas or just bog down?
Pull of the valve covers and have a look. Maybe a busted spring or lifter failure. Keep an eye out for ANY coolant loss. Could be UIM or LIM gasket failure which caused overheating and fried a bearing.
No codes, clean oil, and no loss of coolant are good signs that it may be a reasonable fix.
I have no answers but the experts will probably speak up soon. Good luck.
