Q: My engine rattles while idle and losing power while driving

This is a common sign of a failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this fails, this can cause an imbalanced air/fuel load to be supplied to the motor which often times results in the engine starving for air or fuel. This is what causes the hesitation or loss of power you describe. This can also cause the engine to struggle to idle for the same reason. I would suggest having a professional from Your Mechanic come to your home to diagnose the loss of power and replace this sensor as necessary.