Knock sensor code s14 ka

[s13pignose]

Long story short I've had trouble in the past with 2 codes the most ...34 knock sensor and 35 egr temp sensor. I've been told the egr doesn't amount to anything, but the knock sensor one will retard timing. So I took care of the knock sensor code by bending a resistor in a staple shape and inserted the ends in the plug to the ecu wiring for the sensor. Afterwards I removed the knock sensor off the block and the sub harness connected to it. Its been working up until recently I guess when I notice my car felt slow for about the past week or so.

So I took the resistor out and tried a fresh one since I had spares, and secured it in the plug by wrapping the two with electrical tape, same as last time. Next I reset the ecu, and no codes. Then I take it for a drive, and I get a code. Come to find out its only the egr one. No suprise there, since it comes back no matter how many times I reset ecu. So after about a day or two of driving the knock code is back, just checked a while ago!

I don't get it. The resistor bypass has been working, and I thought if itthe shielded wiring itself to the ecu was shorted, you get a CEL instantly after reset which I never have since adding the resistor. So I reset once more to get rid of the CEL and tried jiggling all sorts of wires and the bundled casing of wires that run along the fuel rail from the front of the motor. Nothing happened and no cel.

Any ideas how I could go so long with out the code for it to come back now? I don't have any new parts on the car or made any changes engine wise. Ordered a new o2 for the heck of it last night, should be here soon. Current one can't be more than 3 yrs old.

Appreciate any help

[Rabboni]

I think if the ecu goes for a while without seeing any knock sensor feedback it will set a code. Youre better off replacing the knock sensor than messing around with these temporary fixes.

[s13pignose]

It would make sense, except the fact the resistor is suppose to be the feedback..well false feedback if you will. I dunno I'm gonna see what happens when driving to work later on. Cleaned my maf for the heck of it earlier. Just don't get it. I've never gotten rid of my egr temp sensor code for more than 3 to 4 days at most, then its back. But i've gone months with out seeing the knock sensor code just with the resistor bypass. I have no real way of telling when it came back since I had the stupid CEL already from the egr code. It's annoying because I have no way of knowing when I get additional codes. I just got lucky and caught the knock code this time off the fact the car felt slower, and decided to check the ecu. I might've caught on late to when it seemed slower but my guess is it started no earlier than the beginning of this month. I've had the resistor in probably since last summer I think

[s13pignose]

Still don't get it..I've made it all the way to work and back today and still no codes. Was close to wide open throttle a few times to see if anything would happen, because the egr code usually appears when i'm WOT If anything I'm willing to be the egr code will come first and knock 2nd (hopefully not). I can live with the egr, I just hope the knock code is gone

[NightSlider]

why not just replace the knock sensor. they go bad over the years. it's just a regular replacement item. ebay sensor for like 50 or 60 bucks. pain in the ass fix, but it's completely do-able. bandaid fixes suck. who knows, you could be harming your ecu.

[kingkilburn]

I would replace the harness for the knock sensor as well.

It seems the bad harness causes an intermittent signal which means that even with the proper feedback from the right resistor you still get a cel.

[s13pignose]

Yeah I don't mind doing a permanent fix, but I just didn't want to spend money on stuff that didn't need replacing. But the two codes have come back 34 and 35. I don't know why they like to come back together. Up until now like I said I've gotten away with just 35 (egr temp) popping up for a while, but 34 is now joining it every time.

It took some driving today to get the CEL to show. Now what makes me sicker is I just remembered the knock sensor throws a code but no CEL on its own. Something else has to trigger the cel first, and thats when you discover the knock code...unless you got a hunch to check for it on your own.

I really hope its not the wiring to the ecu, cause I know the shielded wire isn't something I can tackle myself. Would be nice to not have a CEL anymore. All I have is intake and exhaust. No swap or turbo to complicate matters..and its still a headache.

Appreciate the help guys..hopefully I can get things right. Don't wanna have to throw in the towel on it

[s13pignose]

Oh yeah meant to add to I've gotten megan motor mounts..this was back in like early may. I've had the the knock code way before then, but since they're stiffer I wonder would the knock sensor pick up on it even if I got it back in working order...and be in the same boat I'm in now. I've heard you can mount the knock sensor in diff places like the intake manifold. Seems easier than trying to get new back on the block. Which reminds me, I might have left out in my original post that the old sensor did have cracks(s). So once i noticed that and gave the resistor a try which passed with flying colors, I eliminated the possibility of bad wiring to ecu since that's all that's left on the car. Now I don't know.

I see on ebay they have replacement sensors as low as 17 shipped. Wonder if I should give a shot and try plugging it all back up? Oem ones aren't to expensive on there either, and the sellers of them on there seem to suggest aftermarket ones are cheap and won't work. Then again they might be just trying to make a sale lol?

[kingkilburn]

The knock sensor won't trigger a cel by itself but it will show up when you retrieve any other codes.

[s13pignose]

Yeah thats what I hate about it lol. I like to know when I'm losing power..or so it feels. A CEL would be a good sign of that lol. Think about it, with no cel the car could always have the code and I never know until something else triggers the light. I mean besides the fact the car feels slightly slower, no complaints on how it runs no smoking, overheating, etc. Things that alarm you

[s13pignose]

Alright did some tests after some thinking early this morning.

Every time I've gotten both the egr and knock sensor code, I reset the ecu, start the car and code 55 shows up meaning everything is back to normal. But I'm like why does the car keep throwing egr and knock codes then? Then I remembered, really the knock code could still come back, but I won't know until the egr shows up.

Now for tests. Keep in mind I only have the ecu wiring to the knock sensor, and a resistor in its plug to simulate a knock sensor. The sensor itself and the sub harness are off the car sitting in my room lol. With that said I did the following .

Test 1: I clear the codes to get rid of the cel caused by the egr and start the car and let it run for about 10 secs. The cel didn't come on, so I'm good so far at least with the egr. Now for the knock. I cut it off and put the ecu back in diagnostic mode to see if the knock code is there...nothing but code 55 (perfect).

Test 2: So I start to wonder if there's a short in the knock sensor ecu wiring . I've read if so it should throw a 34 instantly, but thought what if its delayed and only when part of the wiring or other harnesses move around while driving and then it shorts. So I start the car and jiggle the ecu wire that's with in reach cause the rest is bundled up in the casing along the fuel rail. Then I jiggled the engine ground near the o2 sensor and the one near the coolant sensor (think its a ground?). Lastly. the part of the harness running along the firewall to the ecu. Then for the heck of it, I get in the car pick the ecu up off the floor, and move it around to get movement out of the wires. So cut the car off, and put ecu in diagnostic mode thinking I might have finally triggered 34, and nothing...just good ol' 55.

Third test: This time I took the resistor out to see if it even makes a difference. Now I've read all you have to do is have the key turned to on for the ecu to detect a problem with the knock sensor/wiring. However, mine never detected the resistor was out until I actually started the car? I know so because when put it in diagnostic mode a 2nd time after wards..it didn't read 55 as before in the on position, but the 34 instead. Fine enough, I put the resistor back in and clear the code 34 which requires starting the car at the end as always. So Let it run for about 10 sec, cut off, and check to see if 34 is back... it's not, only 55, all is good.

So long story short I'm assuming the ecu wiring isn't the problem..but the resistor? Then I think how so if the knock code doesn't appear with it in, only when I take it out? But yet it will when I'm driving at some point. Everything seems good while in the driveway???

Any ideas? I don't know what else could go wrong while I'm driving to trigger the code. I've tried jiggling wires as stated to simulate what could happen during driving and got nothing. Only thing else I could think is the resistor is not staying in place in the plug and making contact with it's terminals, but I've got it all wrapped in electrical tape to where it cant move.

Any suggestions ideas, throw em at me. Its all much appreciated trust me

[kamilitaryman]

I dont understand why you wrote all this up. Its obviosuly clear that you need a new knock sensor. EGR is a different story...I'd replace the EGR temp sensor if your state wont pass your inspection. But seriosuly dude....you wrote a novel to tell us that your knock sensor is bad and you're asking how to fix it....really? You already know what you have to do....

[kingkilburn]

Obviously you don't understand what's going on.

[Rabboni]

When i said earlier that the ecu wasnt getting feedback from the knock sensor, i meant that if the ecu doesnt see any voltage produced in the knock sensor for a while then it will set a code. Since the resistor you rigged in isnt a piezoelectric crystal it cant produce voltage when there is a knock. That is why you keep getting a code. Now, if you had quit being dumb and just bought a new knock sensor, you wouldnt have had to deal with any of this stupid shit.

[s13pignose]

Just cause you seem to know a lil more than I do gives you the title to call me dumb...next time keep your smart ass comments to your self. I don't care how much knowledge of cars you have, watch how you address people. I mean I appreciate the help, but you also have the option not to as well. Didn't put a gun to your head and make you give your two cents. Plus you said you "think" that's the problem. Meaning not 100% sure..so I sure hope if I get a new knock sensor that's fixes the problem oh great one. So since you have all the answers do you have an answer for why the resistor has worked for others with no problems??

[kingkilburn]

It worked for me for the month I had it in while waiting for a new sensor.

[s13pignose]

That's what I'm saying and its been working for me for several months. I'm not trying to star no net arguments, I just want my car back the way it used to be. I never claim I have all the answers and I was open to help and suggestions which is why I posted. Anyway I ordered a nissan knock sensor no more than 10 mins ago..didn't wanna take chance on generic after reading some feedback of people who bought ebay replacements. Thinking of getting a subharness too for good measure..just trying to see if I can find a deal

[D1GP]

Did a new knock sensor fix your problem? I get the same two codes whenever my CEL goes off.