I have a 5th gen prelude turbo. I'm in the process of breaking in my motor and the stupid CEL code 23(knock sensor) keeps coming on. I checked the knock sensor plug and the wiring to the ecu and both looked fine. I'm probably going to check to see if my knock sensor is bad but if it isn't then i'm assuming its probably coming on b/c of the forged pistons(piston slap). Should I disable the knock sensor? Its really annoying trying to break in an engine with this CEL, b/c the car is running like crap.

 

i dont think that you wuold get the CEL if the knock sensor was doing its job and sensing knock, there must be something wrong with it. try to replace it.


Rob

 

I think it is doing its job though. The CEL light comes on only after some driving, if the codes were cleared earlier. The KS could just be picking up the noise of the forged pistons slapping. Am I missing something?

 

The CEL light would come on if the KS senses knock right? So if the engine is really noisy then this could be mistaken for detonation. The KS seems to be working fine.

 

any other opinions?

 

honda knock sensors are tempermental. i'd try cleaning out the plug again with an air hose and see if that helps.

the only way to disconnect the KS completely is to use an ecu which does not look for the KS. otherwise, you'll have the cel.

 

isn't there a way to get around this. Like grounding the KS and running the main plug on it to the pinout on the ecu. Wouldn't this fool the computer?

 

Ok really quick question. I'm starting to get confused. Will piston slapping cause a CEL with the knock sensor? Just need a yes or no answer b/c it seems some people are saying that a CEL with the knock sensor means either the wiring or the KS is bad.