My car keeps throwing the knocks sensor code. I just had a new timing belt sometimes I do the little thing other times the timing is on. perfect went through three different knock sensors. Does anyone know if this could be a PCU problem and if so, what would be a good ECU to put in a five speed F 23 a1

 

Whats the car? Year Model Trim?

As far as ECU, I could tell you if you told me the car year, model, trim and transmission, but essentially your going to just want the CORRECT ecu which would be the one that came stock in the car, its designed to run that car's motor with said transmission. For example, 1994-1995 Honda Accord EX's came with a "P0A" ecu.
I believe the F23a1 engine was the engine that came in 1998-2002 Honda Accords with an automatic transmission, from my research the F23a1 uses a "PAA" ecu, so that's what your going to want.

The thing to understand and clarify when it comes to a P0325 code in my eyes IS... whether that code is thrown becasue the PCM is detecting a problem with the actual sensor or the circuit and wiring OR IF it could also be thrown because the PCM is just detecting an actual knock event. As in is the code being thrown because the sensor or wiring is bad or is the sensor and wiring OK and working just fine but it is detecting an engine knock. That will tell you if you need to diagnose wiring/pcm/knock sensor OR IF you need to diagnose why your engine is knocking. I just don't know enough about the code to tell you but if you have replaced the sensor multiple times and are still getting the code, I'd say diagnose the wiring, the code usually gets set when the pcm sees too little voltage or to high a voltage indicating a wiring or sensor fault. Knock sensors aren't reference voltage sensors like alot of sensor are, they are voltage generating and rely on a silicone ring and the principles of piezoelectrics to sense a knock or pre-ignition event and tell the pcm via voltage. Pretty simple.

The sensor has two wires, a ground and a voltage output. Both the ground and voltage output are wired to the ecu. You can use a multimeter to test the electrical resistance between the sensors two pins or some type of power supply or battery to apply voltage to the pcm wires and monitor the pcm to see if you get a fault or code.

If you've replaced the sensor multiple times I would be looking at the wiring, the reason I described how the sensor works is becasue it is a low voltage, voltage generating circuit and so it is sensitive, corrosion or damaged wires will cause the code.