This is really useful information,
After the diagnosis, I was told by the service department of the dealership that the misfire is due to the malfunctioning of ring/ piston. They have mentioned that inspector from the Warranty company have confirmed the problem and suggested to disassemble the engine to look inside to find the real cause. And they will not be responsible for the 5 hours of labor charges.
They have given me the phone number of the warranty company to deal with them directly. I am not sure how would I convince them against their inspector’s diagnosis. Thanks again.