i cant get my car to quit pulling a knock sensor code. first i didnt have it hooked up right and drove the car for about a week before i saw a post on how you can mix up the knock sensor/power steering plug, so i got that straightened out and it still pulled a code. put a new sensor on and it still pulled a code. only explanation left is something very technical or in the wiring from the plug to the ECU. is there anyway i can bypass the knock sensor with a resistor or something of that sort until i can get it fixed right, im wondering bc i heard you will run really rich with a defective/unhooked knock sensor and im paying 15 bucks every 2 days for gas as it is...

 

Do you know how to clear the codes ? Disconnect the neg battery cable, push down the brake for 15 seconds .Reconnect the battery cable .

 

yeah he knows how to do that, we've had to go through that many a time

 

Well, if you can find a way to send a signal for a normal knock reading, you would be set. The stock (or rechipped) ECU still retard the car using the knock sensor. I probably won't do much harm except for run really bad and cause really bad gas mileage.

Get a PFC, it doesn't do anything with the knock sensor reading but display it.

 

Is the code actually keeping you from driving it? I'm kinda wondering if you aren't actually setting the sensor off due to actual knock. Some times it can go unnoticed with a loud set-up.

 

no i drive the car everyday. i cant afford a PFC right now. but i really need to solve this problem one way or another. does anyone know of a type of resistor that i could splice into the wire right at the ecu and fix it that way?...

 

If you plan on keep a stock/rechipped ECU on the car, you should fix it the right way.

 

but im stuck on how to fix it right now...

 

It's either:

1. the sensor
2. the wiring
3. both

 

how did you fix it? i've got the same problem at the moment. Can this actually effect gas mileage?

 

The knock sensor element is nothing more than a piezoelectric crystal. That is essentially a high-impedance microphone that puts out a voltage pulse whenever it is shocked by a loud noise (in this case, detonation, knock, ping, etc). When there is NO noise, the output voltage is whatever is set by the ECU. In the case of my '94 FD, it is sitting at +12 volts; don't know if that is correct or not, but I have NO fault code.

The test is to tap on the engine lift bracket with a hammer while monitoring the output voltage with the ignition on and the engine off. If it is working, a voltage pulse can be seen on a DC multimeter. My knock sensor is broken; no pulse. My sensor has also leaked a lot of goo all over my #1 rotor plug wires; I don't know if that killed the sensor or not, but I'm not about to go in and replace it unless it is the cause of my low vacuum at idle. And I don't know whether the mounting hole for the sensor is a blind or through hole into the rotor chamber. If a through hole, I suppose there is some chance it could leak air into the chamber if it is also leaking "goo" and is exposed in the chamber.

Does anyone know if the mounting hole is a through hole or not?

Thanks!