linewar Posted December 17, 2012 Share Posted December 17, 2012 Did it Saturday, and it was not as big as I feared. I just get really nervous messing with wiring because of the whole "point of no return" thing. The knock sensor on my truck has been bad since I last owned it in 2008. There was no MIL on the dash or anything, but I scanned it when I first got my scanner just for fun and found the code. Even back then, the relocation was pretty well established as a cheap fix for the problem. For those not familiar with this, the knock sensor is located under the intake plenums on the back side of the engine. It's about a $25 part, but $800 of labor at a shop because of having to remove the upper and lower plenums. It detects cylinder knock (incorrect detonation of the air-fuel mix) and the engine computer adjusts timing and air-fuel ratio to compensate. The sensor in a Nissan plays a passive role, so the engine may run fine without it functioning, but it will throw a code. Some years ago, someone discovered that you could mount a new sensor and splice into the existing harness to avoid the headache of removing the plenums, so I followed their lead and did it. This guy made a great how-to video on YouTube that I used to know what to do. The only thing about his video that is not 100% clear is the location of the second wire. When you cut into the cover and find the black-covered wire, the second wire is wrapped around the white wire inside the black cover and not separately insulated. It took a few minutes for me to figure it out, but if you notice in the video when he starts the splicing, that splice looks like it's sticking out of the insulation - that's because he put the splice on exactly where it exits the cut he made. Also, the part number he lists is for the wiring harness, not the knock sensor. The sensor itself has a separate part number that I don't remember, but can supply if someone is looking to do this mod and needs the part number. (I bought a package deal off eBay for the harness and the sensor) Overall, it's a relatively easy fix and should help my fuel mileage, since now the engine won't run rich to compensate for the bad sensor. Here are some pics of the finished product: Knock sensor bolted onto intake with harness looped to left: Prettied up where I did my splicing: 4 Link to comment Share on other sites More sharing options...
rocky2 Posted December 17, 2012 Share Posted December 17, 2012 Nice I remember this video and unfortunately had mine done for $500 a couple of years ago before I saw this, so thanx for putting this up and hopefully someone else can save alot of money. 1 Link to comment Share on other sites More sharing options...
linewar Posted December 17, 2012 Author Share Posted December 17, 2012 Yah, that was my hope when I searched "knock sensor relocation" and found nothing. How do I get a cool NPORA sticker like that? Link to comment Share on other sites More sharing options...
edicer2 Posted December 17, 2012 Share Posted December 17, 2012 (edited) I think that harness is the same as a ev1 injector connector. is there a way you can see on the plug that connects to the sensor which side is the clear and which one is the white and take a close up picture of it? You could probably just buy a ev1 injector plug and make your own harness for 5 bucks if you knew which side was the white and which was the clear.Thanks knock sensor plug close up ev1 injector clip which can also be quick release for when you need to replace it again :-) here is it is all together Edited December 17, 2012 by edicer2 1 Link to comment Share on other sites More sharing options...
rocky2 Posted December 17, 2012 Share Posted December 17, 2012 Yah, that was my hope when I searched "knock sensor relocation" and found nothing. How do I get a cool NPORA sticker like that? Ordered it off some generic sticker shop on the web. www.stickershoppe.com Link to comment Share on other sites More sharing options...
ltsnotme Posted December 17, 2012 Share Posted December 17, 2012 (edited) Did it Saturday, and it was not as big as I feared. I just get really nervous messing with wiring because of the whole "point of no return" thing. The knock sensor on my truck has been bad since I last owned it in 2008. There was no MIL on the dash or anything, but I scanned it when I first got my scanner just for fun and found the code. Even back then, the relocation was pretty well established as a cheap fix for the problem. Which code was it throwing? p0325? Has there been any noticeable improvement in fuel mileage? Edited December 17, 2012 by ltsnotme Link to comment Share on other sites More sharing options...
silverton Posted December 18, 2012 Share Posted December 18, 2012 Won't do much in way of adjusting timing way up there, but at least you won't have a code! Link to comment Share on other sites More sharing options...
linewar Posted December 18, 2012 Author Share Posted December 18, 2012 Which code was it throwing? p0325? Has there been any noticeable improvement in fuel mileage? Yep, P0325. 4 years ago when I first scanned it and got that code, I literally did a Google search for the code and the how-to on the Nissan forums was the 4th or 5th entry in the search result. I'm sure glad that dude did the YouTube video, though. I have scanned it several times since and it is not throwing any codes but the emission light still comes up yellow instead of green. I have the $100 Innova scanner from Walmart. I'm tracking the mileage now via Fuelly and added the banner to my sig line. I filled up yesterday after only about 20 miles or so driving with the fix, and registered 14.6 mpg. It'll update as I go, but I've already driven about 70 miles and it's only just below the full line. Considering I was getting about 240 miles on a 17 gallon tank of gas, I think it's improved but maybe not as much as I'd hoped. Link to comment Share on other sites More sharing options...
linewar Posted December 18, 2012 Author Share Posted December 18, 2012 edicer, Here is a close up view of the top of the knock sensor. Sorry it's a little out of focus, but the words look the same except for the Nissan logo on it 180° from the harness plug. Here are two close-ups of the wire coming out of the harness on the sensor. I think this is where your plan runs into a speedbump; there is ony one wire exiting the harness from the area of the left prong. I can verify, however, that there are two wires at the other end of the harness because I spliced them both. It looks like the sensor is the same but you'll need the Nissan Maxima harness to connect it. Link to comment Share on other sites More sharing options...
edicer2 Posted December 18, 2012 Share Posted December 18, 2012 Hey lineware thanks for getting pictures but what i wanted to see if the wire white was on the left or the right so i could make my own harness and knew what color was on the left and the right. The clear one looks like its on the right side but hard to tell. Link to comment Share on other sites More sharing options...
linewar Posted December 18, 2012 Author Share Posted December 18, 2012 Hey lineware thanks for getting pictures but what i wanted to see if the wire white was on the left or the right so i could make my own harness and knew what color was on the left and the right. The clear one looks like its on the right side but hard to tell. That's what I was trying to show - there are not two wires at the harness connection, only one. Somewhere down the line it becomes two, because there are two feeding the downstream connector and two that I stripped and spliced. You can kinda see a blue plug in the other pole exit of the harness, if you're looking at the sensor from the top it is coming from the left side of the plug. As far as I can tell, if there are two wires, they both connect on that one side of the harness plug and then separate into two wires down the line. Link to comment Share on other sites More sharing options...
theexbrit Posted December 19, 2012 Share Posted December 19, 2012 I was thinking of relocating the knock sensor (mine is giving me a code) but I figure I have to remove the intake plenum the first time anyway & how many times am I going to replace the knock sensor Link to comment Share on other sites More sharing options...
linewar Posted December 19, 2012 Author Share Posted December 19, 2012 I hear you. At some point mine will have to come off to replace the driver's side valve cover gasket. But that's pretty low on my mod list right now because its not leaking nearly as bad as the other side was, just a little seepage. Next is timing belt (oh boy) then, all in one fell swoop, new front half shafts, Warn hubs, OME suspension, and probably some bushings since its going on 17 years old. Lots of $$$ to be spent on this lady in the next several months. Link to comment Share on other sites More sharing options...
theexbrit Posted December 19, 2012 Share Posted December 19, 2012 The timing belt isn't that bad, take the rad out, remove the belts, pulleys, plastic cover, etc. The only problem I had was the nut that holds the crank pulley was a bee-arstard to get undone, had to put a long breaker bar on it, rest it against the inner fender & then kick the engine a couple of times I know "purists" are going to scream bloody murder that I used such a half-arsed hillbilly method, but hey, it got the job done :laugh: :laugh: 2 Link to comment Share on other sites More sharing options...
linewar Posted January 1, 2013 Author Share Posted January 1, 2013 Well, did my first full tank of gas since the relocation and got 15.3 mpg - better than the 14.6 I got before. Did a little more highway than normal, so that may have had something to do with it, but hey - every little bit helps, right? Even if it's only half-a-mile per gallon better. Link to comment Share on other sites More sharing options...
XPLORx4 Posted January 15, 2013 Share Posted January 15, 2013 (edited) I'm thinking about doing this to my Pathy, whose KS has been busted for about 10 years. Just to be clear, you completely cut the original wires leading to the stock sensor that is still bolted beneath the intake plenum, right? And you just leave the other end of the cut wires inside the original wire loom that routes behind the plenum? I found the knock sensor (22060-30P00) and KS harness (24079-31U01) on ebay for $78.85. Do you know of a lower price? The knock sensor itself runs $160 at nissanparts.cc! What the heck!? Edited January 15, 2013 by XPLORx4 Link to comment Share on other sites More sharing options...
linewar Posted January 15, 2013 Author Share Posted January 15, 2013 (edited) Yes, you will cut the original wires completely and leave the ones running toward the rear of the engine in the harness. (Make sure you wire the new sensor to the live wire, not the dead, after the cut! Lol) The harness itself also carries the wiring for the fuel injectors, so study the Youtube video carefully. As stated, the only thing that is not really clear in the video is the arrangement of the knock sensor wiring - one is a traditional copper wire with insulation around it, and the other is silver wire, un-insulated, and wrapped around the insulation of the other wire and then both are inside a black rubber sleeve inside the harness. It's not super clear in the video, that's why I mentioned it. Just pay careful attention to the video, it definitely is a complete walk-through. Price-wise, that's about what I paid because I got a package deal and OEM parts. I ordered it off eBay as well. I didn't want to take chances, so I bit the bullet and paid. You could probably do it with a cheaper sensor, but getting the correct harness is very important. Edited January 15, 2013 by linewar Link to comment Share on other sites More sharing options...
kmgar99 Posted April 12, 2013 Share Posted April 12, 2013 I'm replacing mine this weekend...wish i'd seen this relocation post earlier! Oh well...i'll replace it and relocate if it fails again. I get my parts from RockAuto.com...$56 for knock sensor and plenum gasket out the door shipped. Link to comment Share on other sites More sharing options...
NorCalQX4 Posted September 16, 2016 Share Posted September 16, 2016 Has anyone done the knock sensor relocation for the 3.5L engine? Is the procedure the same or are there any needed modifications? Link to comment Share on other sites More sharing options...
1badqx4 Posted September 30, 2016 Share Posted September 30, 2016 WHY NOT JUST CRAWL UNDER THE TRUCK AND REMOVE THE TRANS MOUNT AND PUT HAND UP ON LEFT SIDE BANK AND UNPLUG THE OLD SENSOR FROMT THE BOTTOM AND RE-RUN IT TO THE TOP THAT WAY NO CUSTTING IS INVOLVED? THERES A YOUTUBE VIDEO ON IT I WILL BE TRYING THIS METHOD TODAY. I DONT LIKE CUTTING INTO WIRING. Link to comment Share on other sites More sharing options...
NorCalQX4 Posted October 3, 2016 Share Posted October 3, 2016 WHY NOT JUST CRAWL UNDER THE TRUCK AND REMOVE THE TRANS MOUNT AND PUT HAND UP ON LEFT SIDE BANK AND UNPLUG THE OLD SENSOR FROMT THE BOTTOM AND RE-RUN IT TO THE TOP THAT WAY NO CUSTTING IS INVOLVED? THERES A YOUTUBE VIDEO ON IT I WILL BE TRYING THIS METHOD TODAY. I DONT LIKE CUTTING INTO WIRING. How did it work out? Link to comment Share on other sites More sharing options...
1badqx4 Posted October 4, 2016 Share Posted October 4, 2016 I AM WAITING ON THE SENSOR TO ARRIVE ITS ON ORDER FROM ROCKAUTO.I WILL FOR SURE POST IT UP ON HO DIFFICULT AND HOW MUCH TIME IT TOOK. I JUST DONT LIKE CUTTING INTO THE WIRING HARNESS. Link to comment Share on other sites More sharing options...
Butch Posted May 21, 2019 Share Posted May 21, 2019 Were you able to reach KS connector from underneath? Will the connector (if successful at unplugging) fit on a New KS? I am unsure if there is a pig tail on the old KS. Thanks, Mark Link to comment Share on other sites More sharing options...
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