I have a 2000 Honda Civic iSR 1.6L D16Y8 MTX and the MIL comes on intermittently with a code for the knock sensor ( blinks out 23 when I short the code display pins ). The code goes away when the car is turned off. I can drive at high speed and rpms on the highway for hundreds of kilometers without it coming on, and then drive leisurely around the neighborhood at low speed around 2k rpms and it will come on for no apparent reason.
I recently replaced the engine, and don't know / remember if it was coming on before that ( since I bought it with a bad engine with the intention of replacing it ) , but I went ahead and replaced the sensor with a cheap one I got off aliexpress.
I followed the flowchart in the WSM:
and got to the circled box and was wondering exactly what they mean by, "system is OK at this time."
Can I assume that it is in fact a loose wire / bad connection someplace? Can I safely ignore this problem? Will the knock sensor going off intermittently like this affect my performance in any way? I know there is the issue that ignoring the MIL may mask another MIL, but beyond that is there any problem with ignoring it?
EDIT Sept. 18th 2016
I've been monitoring this for a few days, and some days it won't come on at all, and other days it comes on a seemingly random times, usually a few minutes after I start driving.
Edit Jan. 15th 2019
Just to follow up, I replaced the knock sensor with an inexpensive one off of rock auto that looked decent and since then the following has went away.