1. If you hear a metal knocking noise from the engine, it may be cause by filling with lower RON rating fuel. Once or twice usage of the lower RON rating fuel will not harm the engine, but make sure the car is driven gently when filled with lower RON rating fuel.
2. Aggressive driving made the ECU giving signal to the engine to supply more fuel and more air intake, hence it make the condition even more severe in the cylinder and contribute to higher chance of uncontrolled detonation in the combustion chamber, then make the engine vibrate abnormally and suffer power loss, high temp in the engine also cause the engine produce abnormal noise.
3. If problem exists after changing to fuel with RON level meeting the car manufacturer standard, need to perform further check on the spark plug, fuel injector and catalytic converter.