First of all, you can't ground it out or replace it with a resistor. The knock sensor is not an electrical load, it actually produces it's own voltage. Your ECU is looking for a variable voltage from the sensor.
So what you want to do is mimic the voltage output. Here is a guide of what to do:
1. First, go to Radioshack and buy a piezo transducer, part #273-073. You will find it will all the buzzers because that it's intended for. It costs $1.99.
2. Flip to the back of your haynes and look at the chassis electrical pages. Find which wire going into your ECU is for the knock sensor. If you have a 96-00 civic, it is the Red wire with a blue stripe. MAKE SURE YOU DoN'T MISTAKE IT FOR THE BLUE WIRE WITH A RED STRIPE. That's for your AC system. Cut the wire about 6" from the ECU.
3. Tape the transducer to your fuel rail.
3. Weave a single wire from your fuel rail back to your ECU.
4. Connect the speaker wire to the (+) wire on the transducer. You could just use the stock knock sensor wire instead of the speaker wire. I think I used the speaker wire because it was easy to t-tap into the harness rather than cut off the sensor end. That way, you won't have to re-solder the end back on if you ever want to use a knock sensor.
That's my guess. I don't know.
5. Connect the other end of the wire to the Red/blue wire on your ECU.
6. Connect the (-) wire on the transducer to a good ground.
So basically, the positive wire of the transducer goes to the ECU and the negative wire goes to ground. I taped the transducer to the fuel rail because that's where I found it made the most voltage (most vibration).
The transducer only makes about a half a volt at 4k rpms and the ECU usually sees about 1.5 volts. So if you try this and it doesn't work, you will have to find a better location to tape the transducer or you will have to add a second transducer to bump up the voltage.
All you need to know is this: the positive end of the transducer needs to be fed into the knock sensor input at the ECU, and the negative end of the transducer needs to be connected to ground. That's it. I probably over-complicated the directions.
Also, the way to increase the voltage would be to wire the transducers in series. That is:
But that is not necessary. Just keep moving the single transducer around until you find a location that produces enough vibration and noise. Everyone else has been able to do it with only one. Also, secure the transducer LOOSELY. That's what worked the best for me because the transducer would bounce around on the fuel rail.
