JETSPD1477

Your bogging comes from the 2-3 degrees of timing you lose (retarded) when the Knock Sensor is malfunctioning. The ECU is thrown into limp mode.

CEL sometimes won't come on until after a few minutes of driving or it won't come on at all if the KS is simply unplugged. But code 23 exists believe me.

So if a knock sensor was as important as you claim it to be, why is it that the KS trouble code doesnt log as easily as say, VTEC Oil Pressure?

v4lu3s

well....on both engines, an h22a, and a b18c1, they had cracked knock sensors. both were cracked around the plastic casing, while the metal base was still attacked to the engine. the h22a one would stay together, but the b18c1 knock sensor was pretty much the same too. The h22a one NEVER threw a code 23, but power was down, and it would often bog, until i replaced it.
The gsr engine bogged a lot worse and once a week or so after hitting a large bump would throw the code 23, and go into limp mode.
Both engines showed a loss of power with the damaged knock sensors.
If the knock sensor did not retard timing, you could just pull it off the block and tape it out of the way....yet when using ecu's that look for a knock sensor, why do people actually mount the knock sensor on the head? if it didnt matter what kind if signal was coming from it, they could just plug one in and zip tie it out of the way so it could be seen by the ecu and that is it.

as soon as they were both replaced...no bogging at all, more power, better mileage....and the gsr ecu never threw a 23 again...and the h22a, it still didnt...

kinghawk

Ill be willing to let mine go for $45 plus shipping. Let me know if its still needed

civicon19s

Nope sorry, i dont have a use for it anymore! But hang on to it... they are worth gold at the honda dealership ****ing things probably cost Honda .02 cents to make and they want $190 for em....

Andy

I'm not positive about this, but to my knowledge, a knock sensor is actually a microphone that listens to your engine for detonation (also calling pinging). You get detonation when you have air/fuel that explodes when you don't want it to (in your intake manifold or before the piston has reached TDC on the compression stroke). Detonation is very dangerous and will destroy an engine. You get detonation from extra heat caused by either running lean (or higher compression, a turbo, SC or N20 ...) or lower octane gas which is easier to burn and hence easier to detonate.

The computer increases the amount of ignition advance to a set point. If it detects knock, it backs it off. This allows you to put 87 octane in your motor without it blowing up, but it will loose power. If the sensor is disconnected or damaged, most likely the ECM will throw a MIL and cut the power (also known as limp mode) simliar to what it does when the O2 sensor goes. Basically the ECM isn't getting feedback so it plays it safe. Definately replace it. Seeya.

jusrite

Where IS the KS? Can I replace it myself?? How todo?? Thanks. Jusrite