An OBD II-equipped vehicle has an engine with an oil-fouled spark plug on one cylinder. How will the system prevent fuel from passing through the cylinder and overheating the catalytic converter? What...

An OBD II-equipped vehicle has an engine with an oil-fouled spark plug on one cylinder. How will the system prevent fuel from passing through the cylinder and overheating the catalytic converter?

What advantage comes from reading the sensors’ information and testing actuators through the OBD II connector rather than directly testing them on the car with the harness disconnected?