my friends 91 civic hatch just got a b16 swap and it runs fine(except for a vss problem) but the car is also throuwing a code 23 which indicates kncok but i cant figure out why, the car is getting fuel and the timming is stock. i cant figure it out.....

 

Make sure that the knock wire is connected.

 

i was thinking the same thing but then i check the ecu and it is still wired correctly but im gunna look at the sensor today and see if it came off. it only throws the code when you drive it for a while. i figured if it was wiring it would thow the code right away......

 

That's common if it isn't hooked up or if the sensor is bad.