Keep in mind that the best way to spot a knock sensor malfunction is if you hear a knocking or thumping sound from your car. This is indeed the best indication that the knock sensor of your car has been broken and should be fixed or replaced.
What does a bad knocking sensor sound like?
If the knock sensor is not working properly, you will likely hear sounds emitting from the engine. You may hear loud thumping noises that become louder over time. The noise is a result of fuel and air igniting inside the cylinder, instead of reaching the point of combustion.
Will knock sensor cause no start?
A bad knock sensor will not keep your car from starting. You can drive with a bad knock sensor, but it could have adverse long term effects on your engine if there is a lot of pre-ignition, and the car will not pass most state inspections until it is fixed.
Can a bad knock sensor cause reduced engine power?
A bad knock sensor may also not let the engine accelerate properly while driving on the highway, and cause the vehicle to lose fuel mileage. Once the computer realizes the knock sensor is not working properly, your vehicle will most likely lose power.