For a car sitting that long, it is very difficult not to introduce fuel system problems once you resume using it. That would be my guess. Clogged fuel injectors, fuel filter, fuel pump. That condition may or may not throw an o2 sensor or lean/rich code. If it is bad enough to cause a misfire, it will throw a misfire code usually.
First step is probably to replace the fuel filter (if it hasn’t already been done recently) followed by a fuel system pressure test.