I have the knock sensor out of my car and I was wondering if there is any way to test it? I have hooked a multimeter up to it and then held the sensor to a running dremel tool with a slightly out of balence bit (it vibrated in other words) and the voltage went up ti something like .8, but I have read that it will read up to 5 volts. That dremel had a pretty good vibe going too, it would but many a vibrator to shame I would think. Anyway, I also tapped on it with the handle of a screwdriver and did not see a voltage change, or maybe the multimeter is just not quick enough to pick it up, so how can I test it?