OMG It's incredible... I measured the dead KS... it read 0!

The new one measures 555 ohms.

I tried for 20 minutes and gave up...
i just couldn't get my hands in the tiny hole of the manfold area.

finally i came back to try again. This time i bent a green connector up and was able to get my hand in there. I loosened the bolt as noted here: http://www.skippynet.com/maxima/knocksensor.htm

and replaced it with just about the same scratches as noted on the page.... lol

guys change it! it's incredible the difference! I reached 140 miles an hour in like no time at ALL!!!
before it would struggle past 130.... now it's too easy!

the difference is night and day!

 

Its not good to go past hte speed limit


glad ur car is working good for u now, i think i have bad ks too, i am too lazy to check for a ghost code

 

actually if you have a ohmmeter you can check it in like 2 seconds by popping the hood

I found the connector you need to check while i was in there hehe

yeah speeding is uhm.... bad... but it was for testing purposes... yeah....

 

What caused you to check it in the first place? Did you have a code (ghost or otherwise)?

 

Ok I have a question... Assuming that I always put at least 93 octane in my tank could I feasibly take out the knock sensor but hook up the connecting wire to ground with a 550 Ohm resistor in its place? Obviously there would be no way for the ECU to tell when the engine is knocking anymore, however I am thinking that it may still be safe so long as I NEVER screw up and put anything below 93 octane in my tank. Just a thought... don't think that I will ever actually do this but geeze a $1.25 radio shack resistor sure is alot cheaper than $90.00 discount knock sensor.

 

Yes- I'm interested to.

Did you just happen to check the resistance under the hood for sh~ts and giggles, or did you actually get a code (ghost or otherwise)

?

IanS

 

+1 my car doesnt have a ghost code but well how much is an ohmmetter?

 

screw you !!! no j/p but I want a new KS too

 

from what i've been researching here... no that would be dangerous... Because at a certain point when your wot or pressing down on the pedal, the ignition advance drops instead of goes up... so you will hear a knock when your only using a resistor.

If you check the faqs on the 3rd page you will see a huge huge explanation on why using a ks might be a bad idea and stuff


Why did i change it? For the last 4 months i think it's been, my cel always went off... So i've been trying to hange the pieces one by one. first asking: front o2, KS. ok change that... next the rear o2 KS and EVAP goes off... i start noticeing a REALLY lagging acceleration. everyone here says it probably really is my KS that's dead. Plus i have a hard time believing that my rear o2 will also trigger the KS code.. I could understand more for the front o2's.

So I get this awesome deal to buy a KS for 100$ CDN. Who can pass that up??? I buy it, change it, and DAMN!!! It's like adding a bit more than a ypipe to your car. A ypipe never got me to 140 this fast!

In short, i was mainly prompted to change it, due to lagging symptoms.


I suggest everyone change theres... it's crazy the diff. I thought everyone here was exagerating when they said it's night and day, but they were right! it is! hehe

 

multi meter... costs about... 15$ maybe? I just bought a 400w cheap one at radio shak like 2 years ago... I keep it in the glove box. It's super tiny and has all the basic features i need.

 

I'm using the resistor, but not hearing any knock.

I'm gonna swap the KC and sparks today.

 

My KS tripped the CEL two weeks ago, so I changed it myself. I also noticed a huge difference...especially in low end power. The car can attack hills now without downshifting with the increased power and torque.

Ckeck your ECU to see if it's throwing a Knock Sensor code.

 

i have the resistor in, and i have had it for a few weeks now, no problems, altho i dont really know what knock sounds like..... how would i know? is it very loud? or what?

 

i dunno man... i'd read that faq... i wanted to try the resistor option also... but after reading that the timing sometimes drops to 18 degrees... i decided it's too risky...

plus at 100$CDN, i cannot pass up that option! hehe

 

j/w would it be time to consider changing the KS at >100K?

 

u change it when ya get the code, check ur ecu fro code 0304

 

Where can I get a cheap KS?
I'm throwing 01 04 (speed sensor) and 03 04 (KS)
my speedo also doesn't get off zero til I drive a ways?
also lagging acceleration.

Is replacing the KS pretty easy?
Any ideas on the speedo thing (heard other say same prob)

Thanks

 

go to ebay and they have a new one for 99.00 type in nissan knock sensors. I just ordered mine cause i was tired of waiting for a lower price

 

Seems as though a lot of 95-96 guys are replacing their knock sensor and having great results. Is my car old enough to benefit from a new KS?
I've thrown a couple of CELs in the past year with unknown codes...I have 80k miles on my 98. If my car's performance will benefit from it, I'll definitely spend the $99 on a new one!


-Tony

 

This can only happen if the engine light is on right?

If that engine light is not on then will replacing the knock do anything?

 

hmmm i'm going to take a pic of the engine bay to help you guys out...

it take literally 2 seconds to check for a dead knock sensor without removing it from the engine...

 

yesturday i got a check engine light..

i checked the ECU and threw 2 codes, one for the knock sensor and one for the air temp sensor.. the air temp sensor was disconnected because i was just messing with my intake a little earlier and forgot to plug it back in.. so the air temp sensor triggered the light but the knock sensor code popped up as well..

i reset it and it has not came back yet,
but is my knock sensor bad? who knows.. 130k + on the car

so what exactly am i supposed to measure to check if it's bad?

 

Ummm............ OK

 

If the KS is bad, you really should change it. The performance gain is quite significant. I changed mine about 100 miles ago and driving my Max has never been this fun. It seems like there is a direct connection between the right foot and the butt-dyno.

But if you KS is working, don't waste your money and your time. Changing KS is not fun.

The sure way to check KS is to read the ECU code. 0304 means the KS or its harness is bad. This code is a ghost code thus you need to read the ECU code. The SES light does not turn on for this code. If you have multiple codes from the ECU, fix the other ones first before changing the KS.

 

It's possible (IIRC) to have the KS code without a CEL. You might want to check the ECU every now and again to be on the safe side. I'm pretty sure of this, but I can't verify it as the search function sucks *** on that new test server.

Wait to see if it comes back. As I said above...you might still have the KS code but get no light. Keep an eye on it.

 

I posted this in a thread earlier today, but I figured I'll post it again...

After 2 grueling hours trying to replace my knock sensor, I was finally able to do it. (with the help of my MOM!) Yes I did say my MOM, my hands were too BIG to fit in so I asked my mom if she could help place the wrench on the bolt. All I had to do was unloosen it and tighten it at the end. Without her help I would still be out there cursing the damn thing!
-I give my mom props for changing out my knock sensor!

Now that this is finally done, the car responds much more in the lower RPM ranges. I don't get that sluggish acceleration in 1st gear anymore.

Summary: Difficulty-->YES Small hands are a necsessity!

 

Yeah - the knock sensor code (0304) itself will not trip the CEL. This is a problem I've been having with in my 96 where I have a knock sensor that is intermittently good/bad. Sometimes I feel the car is really sluggish (no CEL) and when I check the ECU - I get a 0304. After a reset once - I drove about 100 miles and the car was driving fine - so I check the ECU and no codes this time (0505). Then like a day after that - it;s sluggish again and sure enough - there is an 0304 code. I finally gave in and ordered a new knock sensor. I will be installing it this weekend.

 

 

Lets all remember how things work here guys. KRUSHANE you are right when the knock sensor does not create a CEL if its bad. Although, if a sensor or some other problem occurs, it usually comes with a knock sensor code (EX: O2 sensor and knock sensor- changing the O2 sensor will most likely fix both codes).
Im getting a "ghost" code for my knock sensor, and nothing else. I have checked the resistance several times, and my multimeter says that my KS has a resistance of around 550k ohms, which means that it is good. But, I dont have any other code, and my car is running horribly (bad gas mileage, hesitant accelration). I considered the resistors from radioshack, and I did it for a week. I did regain a lot of the power back, but I started to think of the long term effects. The resistors will have a resistance fo around 550k ohms, so that the ECU thinks that there is a perfectly working KS. But in reality, the way a KS works is by sending a certain amount of voltage to the ECU when it hears a ping or knock, which is how the timing gets advanced retartedly. Resistors dont do that, so if something is actually wrong with your engine, you wont know, because the resistors dont pick it up. I rather be careful than have my engine mess up.

Im strill trying to figure out why im getting a KS code if my KS is reading fine on the multimeter. I have no idea why my engine would be knocking, I only use 93 octane gas.

For those of you that have dealt with this before, you will notice that the harness from teh KS has only one wire, if you follow that wire, you will see that it leads to a "sub-harness". This sub harness disconnects into two parts (of course one side leading to the KS and the other to teh ECU). I found this to be a real easy way to test resistance rather than taking out the KS completely or gettign your hands cut up trying to work with the KS. When I measured the side of the sub-harness that leads to the KS, i got around 550k ohms. When i measured the other side (leading to the ECU), I got another reading (not quite sure what the amount was). Basically, I noticed that when the sub-harness is connected, I test the resistance and it cuts in half to around 270k ohms, Im not sure if this is normal, but it seems that between the KS and the ECU the resistance is only 270k ohms. Till this day I am still puzzled, because people have said that its normal, why would it be normal? If the KS is supposed to read 550k ohms when testing it by itself, then why would it drop to 270k ohms when you connect it to the ECU??? Oh well..

 

The knock sensor could be receiving signals that are NOT from engine knock. See the other KS post.

 

Maybe the ECU side also has a 550K input resistance. Thus when they are connected together, the resistance is dropped to half. Many years ago, I heard in one of my class that the wire needs to be terminated by having the same resistance on both ends so that the signal can propogate correctly without its shape being distorted. Any electrical engineers in the house?

Even if you have a working KS (550K, etc.), it may be too sensitive and thus setting false knock signal to the ECU. If it was over torqued, it could become too sensitive. If you see 0304, there is something wrong.

 

That makes sense unclemax, ive taken off and put back on my KS many times, and I still get the KS code. Im wondering what signals could be setting off my KS...