In my country CF3 accord or 98-2000 accord came with 1.8 engine F18B. My question is that did it used knock sensor ? the one i have seen in junk yards they don't and they have fixed distributors without adjustments. This means it is adjusted by ECU.

How does it senses the knock then or manages the engine timing ?

 

Check on the back of the block by the oil filter, that is where it is on later F23 engines. If your car is not a '00 it may not have OBDII and may not have the knock sensor.
It may not sense knock, and may be programmed conservatively enough to prevent knock in normal driving. Here in the U.S. I don't think the F series had a knock sensor until the F23 in '98.

European vehicles did not get OBDII til '00. If the car is a '98 or '99 it may not have had the knock sensor.