winvargh

So, i have not really been driving my car all winter (my 02). 2 weeks ago i checked the oil level, and the dip stick read below L. So, i filled up one quart and it read above the L. The oil i use is royal purple, 5w-30. Between the time on putting in oil i accidentally poured some over the valve cover. Some oil got into the furthest spark plug, the one close to the fire wall. It was a good amount of oil, not so little. This would be cylinder #4 i assume. 4 or 5 days go by, and i was driving and the CEL came on. I quickly went to auto zone and had them scan the code for me. It said cyl #4 misfire. So, i have not driven the car after that. It has been a week. I am assuming oil got into the spark plug on cyl #4. The engine has 157,xxx miles on it. It had a lot of maintenance done on it at 150,xxx from a honda dealership. There was previously a misfire in cylinder 4, and the valves were adjusted and the fuel injectors were also cleaned. The car has not had any problems besides this. It runs amazing.

Would this also mean the valve cover gasket is bad?

Can someone give me some insight on this?

Thanks!