sunovertone Posted August 2, 2014 Share Posted August 2, 2014 While trying to figure out why my nissan would not start, it threw a Knock Censor code. I have heard it is an expensive and difficult censor to replace. Before it didnt start ( working on it) the pathy ran fine. Does the knock sensor code mean there is something seriously wrong with the engine? It is a new car to me, and a bit unfamiliar. What is a knock censor, and what could it mean is wrong. Link to comment Share on other sites More sharing options...
thorpe991 Posted August 2, 2014 Share Posted August 2, 2014 The knock sensor dosent cause the engine to run differently mine has been bad since i got mine (aug 2013) and it runs fine 1 Link to comment Share on other sites More sharing options...
Leo98 Posted August 2, 2014 Share Posted August 2, 2014 Thank you, I was looking for the answer to that. Link to comment Share on other sites More sharing options...
ferrariowner123 Posted August 2, 2014 Share Posted August 2, 2014 Not true, mine was bad and my milage was horrible. I replaced it and put 3-4 mpg back in to my per tank average. And it stopped hesitating when you got on the gas. A knock sensor code is not uncommon, it's associated with a different part that needs to be serviced, I can't remember what it was but do a quick search, plenty of people have asked about the knock before. -Kyle Link to comment Share on other sites More sharing options...
sunovertone Posted August 2, 2014 Author Share Posted August 2, 2014 I did do a search on the forum, not much came up. But with what I could find, it doesnt sound like a super serious prob. It would be good to get better mpg though! Link to comment Share on other sites More sharing options...
ferrariowner123 Posted August 2, 2014 Share Posted August 2, 2014 I went from 10mpg to around 13.5 overall average. I did it the right way though, taking off all of the intake manifold, and replaced it, non of that relocation malarkey. -Kyle Link to comment Share on other sites More sharing options...
Quaintbucket Posted August 2, 2014 Share Posted August 2, 2014 Not true, mine was bad and my milage was horrible. I replaced it and put 3-4 mpg back in to my per tank average. And it stopped hesitating when you got on the gas. A knock sensor code is not uncommon, it's associated with a different part that needs to be serviced, I can't remember what it was but do a quick search, plenty of people have asked about the knock before. -Kyle Did you replace it in the spot it originally locate under the intake manifold or relocated it? I relocated mine. It really should not have an effect on your engine. All it does is tell your ECM that there might be an issue with the engine or something else. If you get a p0325 by itself, it means the knock sensor or the harness has gone bad. No more, no less. Common problem. 1 Link to comment Share on other sites More sharing options...
sunovertone Posted August 2, 2014 Author Share Posted August 2, 2014 Just got the code by itself. I am glad it doesnt sound to serious, but it does sound difficult to repalce. Link to comment Share on other sites More sharing options...
thorpe991 Posted August 3, 2014 Share Posted August 3, 2014 I went from 10mpg to around 13.5 overall average. I did it the right way though, taking off all of the intake manifold, and replaced it, non of that relocation malarkey. -Kyle I think there might be somthing else wrong with yours as i get around 17 with oversized tires (32") and bad knock sensor 1 Link to comment Share on other sites More sharing options...
MY1PATH Posted August 4, 2014 Share Posted August 4, 2014 (edited) The knock sensor dosent cause the engine to run differently mine has been bad since i got mine (aug 2013) and it runs fine HOW CAN YOU SAY THIS? If the sensor detects a knock the ECU takes countermeasures to eliminate the knock. Methods vary from ECU to ECU but involve retarding ignition timing, adding more fuel and sometimes even both. On the other hand, if you have a KS code it is likely that it has been deemed defective and its input is being ignored meaning you do not have the protection that this feature offers. Edited August 4, 2014 by MY1PATH Link to comment Share on other sites More sharing options...
thorpe991 Posted August 4, 2014 Share Posted August 4, 2014 Because my pathfinder runs fine no skips or weird noises or anything like that power is fine i took it to a shop and they ran it on some machine that checks the engine when its running for issues and it didn't pick up any issues so they said i didn't need to replace it if i didn't want to as it wasn't causing issues with the motor Link to comment Share on other sites More sharing options...
ferrariowner123 Posted August 4, 2014 Share Posted August 4, 2014 Did you replace it in the spot it originally locate under the intake manifold or relocated it? I relocated mine. It really should not have an effect on your engine. All it does is tell your ECM that there might be an issue with the engine or something else. If you get a p0325 by itself, it means the knock sensor or the harness has gone bad. No more, no less. Common problem. As i said in my post, i did it the right way, pulling the intake manifold and putting it on the Factory designed location. and whatever man, if you are so sure it doesn't do anything, delete it and tell me how your pathy does. (Also, if you dont think its has an effect, why did you bother doing anything about it, hence, relocating it....just saying) I think there might be somthing else wrong with yours as i get around 17 with oversized tires (32") and bad knock sensor Yeah, cracked headers means wonky everything, i cant wait to get back to 16 MPG. -Kyle Link to comment Share on other sites More sharing options...
Quaintbucket Posted August 5, 2014 Share Posted August 5, 2014 As i said in my post, i did it the right way, pulling the intake manifold and putting it on the Factory designed location. and whatever man, if you are so sure it doesn't do anything, delete it and tell me how your pathy does. (Also, if you dont think its has an effect, why did you bother doing anything about it, hence, relocating it....just saying) Yeah, cracked headers means wonky everything, i cant wait to get back to 16 MPG. -Kyle Whoa, man. Sorry, I guess my tone came out wrong, I wasn't trying to chastise you or discredit you. I just simply disagree with the indication that the knock sensor was critical to the system. I just look at the FSM in the past and it suggests that it is not critical to the operation of the vehicle. My quick google after my post shows that it's a mixed bag of anecdotes whether or not it had a meaningful impact on the engine performance. The reason why I replaced the knock sensor was for one reason and one reason alone: I got tired of seeing P0325 everytime I scan the car for codes (dead knock sensor, nothing else) and did not want it to influence diagnosis. The relocation was done because I do not feel like pulling off the intake manifold to replace 1 knock sensor which is a 3-6 hour job in itself. Time I just simply do not have. At this moment, it's a good temporary fix until I can get the stuff together for the IACV (cleaning or replacing TBD), a couple hoses, and valve cover gaskets. Once I have all the kits in place and the time to do it, I will be also replacing the busted KS. The relocation of the KS is perfectly fine. The only issue is that it's not as accurate because it's so far from the engine but it will be adequate as a safeguard from any problems that will arise. On top of that, I can't really say if the KS made a difference in my fuel economy because I did a full tune up on my pathfinder (spark plugs, wires, dist. cap, dist. rotor, fuel filter, and air filter) as well as the MAF sensor cleaned up all pretty like. Fuel economy and performance definitely improved even with being an AC+idle hog during this heat wave we got going on. I am hearing a ticking noise from my engine. Sounds like metal vibrating on metal. Most likely my engine mount is loose so I have to tighten that up today. Sorry if I offended you. I'm just curious, what happened to your header causing it to crack? TL;DR: I do agree that the KS should be in the original location; however, the relocation is a perfectly acceptable temporary fix until the owner has time to take off the intake manifold and all that @!*% around it. Besides, they will eventually have to replace the valve cover gasket. Link to comment Share on other sites More sharing options...
anyexcuse Posted August 9, 2014 Share Posted August 9, 2014 (edited) I bought my Pathy this last winter. I have the knock sensor code and a couple other ones come up since I bought it. I had a mechanic check it out and he said as far as he could tell, everything was working OK. It seems to run fine, and I checked my MPG on a 200 mile trip a month ago and it got 19.3. I was pretty satisfied with that! Edit to add: He said something about checking the KS by hitting the engine with a mallet or something when the motor was under load or something. Don't quote me! Edited August 9, 2014 by anyexcuse Link to comment Share on other sites More sharing options...
Slartibartfast Posted August 9, 2014 Share Posted August 9, 2014 (edited) The knock sensor is supposed to tell the ECU when something on the motor is pinging, knocking, rattling... generally doing something it shouldn't. I think it's designed to detect predetonation or a rod knock, but I've heard (generally, not Pathy specific) of loose heat shields setting the buggers off. I think the test your mechanic was talking about was to hit it with a hammer and see if the engine speed and/or sound changed (which would indicate that the computer "heard" the knock and held the motor back a little). It sounds like the ECU can tell "no signal from the knock sensor" from "knock sensor senses a knock." Odd (and unhelpful!) that it would throw the same code for both. Edited August 9, 2014 by Slartibartfast Link to comment Share on other sites More sharing options...
Quaintbucket Posted August 9, 2014 Share Posted August 9, 2014 The best way to test it without a hammer is to use an ohm meter... Link to comment Share on other sites More sharing options...
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