im pulling an 0304 ghost knock, but my gas milage is consistant 23-24 and i am noticing no real performance loss, knock sensor also tests out fine with the voltmeter. wondering if theres anything else in the knock circuit that would throw an 0304 or is it just time to replace the sensor after 60k? anyone see this before

 

self sympathy bump

 

My car has had the same symptom. After driving 12 hours on a 15 hour trip the CEL/MIL came on. I checked it at autozone and they said it was the knock sensor (0304). Before taking the trip i switched from 87 octane to 89 octane to eventually permanetely 91 octane. I don't know if that would have been a possible cause for the Knock sensor to go bad. The car shows no symptoms of a bad sensor because it drives fine. My question is if you reset the ECU and the light goes off, will it come back on if i dont change the sensor? I read in the sticky that a bad knock sensor will not cause the CEL/MIL to come on. What is up with that?

 

My '98 SE threw 0304 with no symptoms ... I reset the ECU and the light hasn't come back on, but if I self-diagnose the ECU it will still throw the code. I've stalled on doing anything about it because the car drives fine.

 

0304 comes if hte ECU is not getting a responce from the Knock Sensor.

 

So I don't have a detonation problem? It's just that my ECU isn't getting a response from the KS? If there's truly a detonation problem, the CEL will consistently come on?

 

No CEL is car is knocking. But it still slows down the timing.

 

ok so my ecu is not getting a response from the knock. and knock tests fine with multimeter, just searching for possible solutions or things to check before buying a new ks.

 

I'm having the same problem...after I put my vi on i've been having 0304 pop up all the time now.

Would it just be smart to get another KS?

 

thats pretty much what im asking too, before i jump in on the GD

 

If you clear the code for the KS 0304 and the light doesnt come back on does that mean you have no KS problem? IF the sensor was bad it would come back on even after the code is cleared right?

 

I want to know that answer, too. I cleared mine and the light never came back on, but if I run a self-diagnosis it will still spit out 0304. Makes me nervous, but the car drives fine. Hhmmmm.......

 

yup. exact same thing here

 

one last bump

 

The KS may be having an intermittent problem, like a loose connection internally, that triggers the code occasionally but still allows the KS to check out okay when you test for resistance. That is what happened with mine. I eventually replaced the KS and I noticed a definite improvement in midrange torque, and I haven't gotten the code since.

By the way, the 0304 code comes up if the ecu detects resistance that is too high or too low, indicating a problem with the KS or the KS harness. The code will not be thrown if the KS detects detonation. That is its function, after all. Also, a faulty KS will throw a code, but it will not illuminate the CEL.

 

thanks! i really appreciate your help

 

I recently purchased a 95 Maxima SE 5-speed and it was delivered yesterday. I pulled codes today by way of the MIL and had code 0304. In California, the car will fail the smog test if any codes are set so instead of playing around with it, I went down to my local Nissan dealer where my buddy works. I purchased the Knock Sensor Harness (PN: 24079-31U01) and the Knock Sensor (PN: 22060-30P00). Costs were $15.10 and $131.26 respectively. Then I went to replace it and noticed that my hands are just a bit too big to squeeze in there. I couldn't touch the sensor which meant I had no hopes to reinstall it even if I got it removed.

Got an idea that my mom is a pretty small lady with small hands. So I drove over there, let the car cool down. Got out my tools (12mm 1/4" socket and a 1/4" ratchet) and had her put the ratchet on the sensor. I broke it loose and she removed the bolt. I hooked up the new harness to the new knock sensor and she reinstalled the bolt and I snugged it up. Buttoned everything back up. Total time, about 15 minutes and I only got one little cut, about 1/4" long.

I disconnected the battery for 15 minutes and took the car for a spin. NICE improvement. Came home, took the intake off and cleaned the throttle body with STP throttle body cleaner. I also cleaned the heated wires on the MAF and the IAT sensor. Dried with compressed air and man the car idles great and the throttle response is SOOOOO much better.

Bottom line - spend the cash and fix the problem. Chances are, it won't fix itself. Now I can get the car smogged with no worries. Also, the techs there recommended replacing the harness as it's cheap insurance. My stock one with 121k miles was brittle, but it still tested out okay.

 

yeah im picking up a sensor asap as soon as the group deal goes through at least, good to hear a success story on replacing it =P

 

The KS will not trip the light by itself, that doesn't mean it isn't bad. It could still be bad even if you don't feel the power loss. I wasn't really sure so I checked for codes just in case and there it was. It does make a huge differnce though, and makes the car so much more fun to drive.