2011 TOYOTA SEQUOIA Steering Problems

On [XXX] while driving our 2011 Toyota Sequoia 4x4 Limited (5.7 iforce non flex fuel) my wife was preparing to stop at a traffic light. Completely unexpected and with no warning, the vehicle started bucking, the engine began making a knocking noise and numerous dashboard lights started flashing. It immediately stalled while attempting to stop, thus, causing a very dangerous situation, losing total control of the brakes and steering, nearly causing a collision with the vehicle in front of her. The vehicle had to be towed from the middle of the road, while in heavy traffic. Eventually it was diagnosed (at my mechanics shop) and determined to be a broken valve spring in cylinder #7. This caused the valve to drop into the cylinder bore, making contact with the piston, known as "catastrophic failure on an 'interference' engine"..I later learned that these DEFECTIVE ($5) valve springs, are used in my...