The first thing you must understand is diagnostic fault codes never say to replace parts or say parts are bad. They only indicate the circuit or system that needs further diagnosis. About half of the time the sensor referenced in the code is defective but half of the time there could be a corroded splice, stretched or corroded terminal in an electrical connector, or a broken or grounded wire. There are also numerous potential codes related to both of those sensors. Some describe a defective condition with the electrical circuit. Some describe an unacceptable condition that is being reported by a sensor that is working properly.
In the case of the knock sensor, if you can hear a knock in the engine, the sensor is supposed to report that. It is supposed to detect spark knock but it will respond to mechanical problems inside the engine too. In response, the Engine Computer will retard ignition timing in an attempt to stop that knock. That will result in low engine power. Replacing the knock sensor won't fix the problem it is detecting.
Tuesday, April 30th, 2013 AT 1:53 PM