I have been gone for sometime and just came back last week. I read about all these knock sensor codes here and I go out to the car and dang! 0304! KS! This BITES! I had been noticing the maxima was sluggish acting sometimes.

 

welcome to the club

 

Did you manage to install yours yourself?

 

i tried a few times with no luck. it was rusted on there and the last time i tried, i sprayed WD 40 on it, but haven't tried since then., so i havent gotten to feel the benifits of spraying it.

I may return my ks for the 188 I paid for it b/c now I need to replace the timing chain, and need the $$

 

hey got a question for u guys if i had that same cel code and been reseting the ecu every time i get it... (4 times) and ever since the 4th reset it really hasnt come on so is that okay ????

 

You need to replace it - if it has thrown the same DTC 3+ times, it will likely do it again. Normally, resetting once & getting a second DTC is enough of a verification that the problem is "real" and not a software hiccup.

 

I had that problem. It took a while before the dealer figured out what it was. There was a short on one of the 02 sensors, and they spliced it and fixed it up. Also, I got my battery replaced.

I've been going for a few months now without any 0304 codes, thankfully. Before, I used to get it more than a few times a month, and it got annoying. I'm glad it's gone.

 

A short in the O2 sensor caused a knock sensor code to come up

 

There sure have been alot of them lately. Including myself.

SuDZ

 

Yes a bad o2 sensor can trigger a knock sensor code. I speak from experience.

 

Okay, I can understand that, but if the O2 sensor is causing the problem, the code for the O2 sensor will come up as well, correct??

If there is no O2 sensor code, but a knock sensor code, then the O2 sensor didn't cause the problem and it is a legitamte knock sensor issue. I don't want to start chasing parts to make this issue go away.

 

That is what I encountered. I had a damaged o2 sensor, got a code for the o2 and the knock sensor. I changed the 02 sensor, reset the ECU, and didn't get the ks code again.

Without any other codes, I would go ahead and replace the knock sensor.

 

Cool, good to hear. I'm suppposed to get the knock sensor tomorrow and replace it, hopefully it is just that and nothing else will pop up. It figures this would happen now that the car needs it's emissions test again.

 

My light came on, with 0303 and 0304, I reset it and the light is off, but it is still giving a knock sensor code.

 

does the CEL always come on or it won't?

 

the KS won't trip the CEL. It is stored in the computer but won't trip the CEL.

 

I went to the dealer yesterday, and they said that the knock sensor trips in the cel for certain years. Does anyone know if this is true? Does the knock sensor trip the cel for the '96? Also, I did the self-diagnostic ecu test (screwdriver test)and I got the 0304 code, but the service manager said that the method is not a good test (not yielding accurate results). Is this true? Thanks.

 

Everyone says the knock sensor won't trip the CEL but it tripped mine on a 97. That 0304 code points to a possible problem with the knock sensor. What the service manager was probably getting at is the most accurate way to test it is to put a multimeter on it. This is how you could test it:

Diagnostic Trouble Code 0304 points to a problem with the Knock Sensor.

The KS is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is senses as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (The computer).

This malfunction is detected when an excessively high or low voltage from the KS is entered to the ECM.
Possible causes include...
- the harness or connector (The KS circuit is open or shorted).
- the KS


The KS may be checked with an ohmmeter.

1) Raise the hood. View the engine from the driver's fender. Look into
the deep valley between the cylinder banks and below the intake manifold.
Identify the KS as a black item fastened to the block by a single vertical bolt. A wire harness wrapped in black leads toward you, out of the valley.That is the KS sub-harness.

2) Follow the KS sub-harness to it's nearest connector. This is connector F121. It is located near the upper right-hand corner of the valve cover of the forward cylinder bank, as viewed from the front of the car.

3) Disconnect F121. You have to do a "press the latch and wiggle and
pull" to disconnect it. F121 has only two pins; if you see more than two pins, you have the wrong connector. Use a digital ohmmeter capable of measuring more than 10 Megohms. You want to measure the pins of F121, not the sockets of the matching connector. Measure the resistance between a good ground (such as the battery negative terminal) and pin #2 of connector F121. On my car this is the highest of the two pins, the one closest to the front of the car. The factory spec is 500 - 620 Kohms.

The manual says you have to remove the intake manifold to replace the KS. However, I think that a person with good dexterity and a 10mm ratcheting box wrench could replace the KS without disturbing the manifold.

 

Great writeup!

 

That was actually originally from the ECU sticky that used to be on this site, and will hopefully be back soon.

 

how can i tell if my o2 sensor is bad or not?

 

This is from the same source as the post above:

DTC 0409

Diagnostic Trouble Code 0409 indicates a problem with the front Oxygen Sensor on the right cylinder bank.

The right bank is also called the rear bank. It is cylinders 1,3,5. The Engine Control Module determined that the response of the voltage signal from the sensor takes more time than it should. In simple terms, the Oxygen
Sensor is still working but it is not doing its job well. Possible causes include ...
- Harness or connectors (the sensor circuit is open or shorted).
- Bad Oxygen Sensor sensing element
- Bad Oxygen Sensor heater
- Fuel pressure out of spec
- Fuel injector malfunction
- Intake air leaks
- Exhaust gas leaks
- Positive Crankcase Ventilation valve
- Mass Air Flow Sensor



The Oxygen Sensor sensing element may be tested with an electronic tester made for this purpose, or with an
automotive oscilloscope. The Oxygen Sensor heater my be tested with an ohmmeter. This test is done with the
engine off. Follow the wires away from the Oxygen Sensor until you find the nearest electrical connector. Disconnect theconnector. Viewed with the connector latch at the 12 o'clock position, there are three terminals.

They are numbered 1-3, right to left. Be sure to measure the terminals in the connector half which is attached to the
Oxygen Sensor, not the one which leads to the Engine Control Unit.

Measure the resistance between terminals 1 and 3.
The factory spec is 2.3-4.3 ohms at 77 degrees Fahrenheit.

Measure the resistance between terminals 1 and 2.
The reading should be infinity (no connection).

Measure the resistance between terminals 2 and 3.
The reading should be infinity (no connection).