Q: What happens if I don't replace knock sensor?

The knock sensor on the engine is there to detect for an engine noise from pre ignition (pining) normally. This is so the computer can advance the ignition timing to the maximum it can without the engine pinging. This gives you the best engine power and fuel mileage.

If the knock sensor is not working then the engine could start pinging without the computer being able to detect it. This pinging can cause the combustion process to burn or blow holes in the pistons.

If an engine has an internal engine noise from a rod or piston knock problem it can cause a knock sensor to keep detecting a knock and the computer will keep reducing the ignition timing until a set limit is met and the computer will set a code for the knock sensor. Have the engine checked for internal problems that could be causing the knock sensor code.

If the knock sensor is bad through testing then if it is not replaced the engine may have reduced power, loss of fuel mileage, and hesitations. If you need help the replacement of the sensor or need to resolve any of these conditions, consider YourMechanic, as one of our mobile technicians can come to your location to diagnose and service your vehicle.