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Discussion Starter · #1 ·
Hi all,
I have recently checked into getting my knock sensor replaced and i was wondering if any of you have replaced your knock sensor as a DIY job. The first muffler shop that i called about it charges 3.1 hours at 105/hr and 146 for the nissan sensor, or 119 for an aftermarket.
Autopartswarehouse has the o2 sensor for a whopping 56$ plus shipping, but 320$ for labour seems like a lot.
Any info on the Do It Yourself route would be appreciated preferably on the 96-99.5 years.
 

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knock sensors are usually a sensor on the block... but i've heard they can be in the exhaust, detecting engine knock differently.

a knock sensor isn't really needed, it just lets you know your engine is hitting middle age.

when i rebuilt my KA, it didn't have one... i put one on, when i read the codes after i was all done, it showed up... then went away... showed up.. went away.. old motors..

old women still feel good, but they don't feel like they used to.

;]

an O2 sensor detects oxygen in the exhaust... when it detects too little...or too little (can't remember) the EGR works over time... putting exhaust back into the system to reburn the same air...
that's all your emission crap is...
reburning the same air.

tis why foreign and old cars feel so fast. always breathing new air.
 

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Discussion Starter · #3 ·
Edit to the above...
Auto parts warehouse has the knock sensor for about 56$ (not o2 sensor)

-----------------------------------------------------------------------------------

the 98 pathfinder has the knock sensor in the exhaust or intake, i cant remember which at the moment. while i appreciate the response, your post didnt answer my question.
 

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if it's in either the intake or the exhaust, it should be in the exhaust cuz air current transports sounds... you know how you hear someone downwind but not upwind?
as for DIY...
it's pretty easy, you unplug it, usually have to use an adjustable wrench or lucky enough for a reg right size one to unscrew it, and then the opposite on the install. it's kinda like an engine plug... just screwed into the block or exhaust.
 

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The knock sensor is under the intake in the center of the engine block. It requires quite some work to change. The o2 sensors are in the exhaust.
 

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Discussion Starter · #6 ·
would the knock sensor affect fuel economy at all? or is it more of a nuisance code?
 

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It shouldn't, and yes, it's a very common error code.
 

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Discussion Starter · #8 ·
i believe it may be related to my rear o2 sensor. I just reset the code today, just before a road trip and with an hour and a half of driving the SEL came on. I wonder if having the knock code in blocked the ECU from flagging an o2 sensor code. I am sure when i check the code it will come up p0158 for the downstream o2 sensor (i think driviers side if i remember correctly)
i will replace that first before i do the knock sensor. hopefully i wont have to
 

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he's not lyin. the knock sensor's usually a real bitch if you don't have the engine out of the bay... it's on the block itself inbetween a couple cylinders.

but you need to double check that your engine even has one before you go into all that. i could swear that i've heard of some knock sensors being relevant with O2 sensors (meaning they either have both in the same spot, or the O2 sensor is also the knock sensor)
but that's just from a hypothesis.

either way, a knock sensor doesn't effect anything majorly. UNLESS, it's the type to tell the computer to stop using that particular part of the engine. and i really honestly doubt those exist in anything sides 'individual cylinder knock sensor' engines.
all it does is turn on the 'check engine' light, so you pop the hood with a big '?' on your mind and happen to notice your engine is knocking.

the O2's always on the exhaust, just down from the exhaust manifold.

the knock sensor is usually on the block itself.
but i've heard of them being on the exhaust too. (only detecting major engine wear... or! ...a sensor that turns on the 'check engine' light waaay too often)
 

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Discussion Starter · #10 ·
Ochno,
while entertaining your responses aren't very helpful. None of them have answered my questions and they have been extremely vague. I don't mean to be rude but I seem to know more about this problem than you do.

The 1998 pathfinder does have a knock sensor. It is located in the block. It also has 4 o2 sensors (1 before each cat and 1 after each). I already know where the o2 sensors are located and will likely be changing them when I get them in (they are already ordered). The knock sensor does not flag the CEL on the pathfinder though it will read if you plug an OBD2 reader in if it has triggered. In my situation it appears that the knock sensor code triggered and was suppressing the p0158 code (which is drivers side rear 02) which I had flag the CEL before and then reset to see if it returned.
I did manage to gather from other posters that the knock sensor is in the block and does require a sizeable amount of work to replace which means that if the o2 sensor does not fix the code I will be taking it to a shop to get it replaced. I will also be having the cats checked for operation before I replace the o2 sensors as I don't want faulty readings due to a failed cat.
 

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I can only tell you my experience with this. I also have a 98SE.
I'm absolutely sure that the knock sensor problem does not turn on the CEL, O2 sensors do. But it shows up on the OBD scanner.
Also when you reset the CEL, it will take 3 driving cycles to come back on or to go back off (if the problem was fixed), which means 3 times engine turn on and off.
How many miles do you have on the odo?
 

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thank god you know how to scroll down to the next post then ey?

cheeky punk.

ha.

if you want specific answers, give specific questions.
knowing myself, i wouldn't have bothered with it had you not been confused on the knock/o2 sensor. even more so had you put down that you have 4 f^cking o2 sensors on your car.

;]

and i was sh!tfaced that day and didn't exactly give a f^(k
 

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Discussion Starter · #13 ·
that was apparent. and i thought the question was specific enough. the only mistake that i made was posting 02 sensor when i quoted the price instead of knock sensor which i edited (i wasn't confused about which was which ,i just happened to have both on my mind while i was typing). and the question wasn't what the part were for or even where they were located. It was whether or not anyone had replaced the knock sensor and how involved it was (specific to my year pathy)
 

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oh, well that's easy like that guy said...
it's involved.

it's a sensor on the block... so if you go out to your car and can't get a wrench anywhere near it, then you'll have to take off everything in your way, all for a sensor that doesn't do anything sides turn a light on and tell you your engine's old and needs a rebuild.

my ecu had a knocksensor code... i rebuilt the engine, it went away.

if you've got a knocksensor code, chances are it's not the sensor, it's just an old engine..
course... switching out the sensor is cheaper, but that's like saying you're going to change the horse shoe on a horse's broken leg.

a dead metal object that can slightly effect miniscule tuning, isn't crap compared to why it's giving you a code... a knock sensor is exactly what it sounds like.. it senses the engine knock.. something that can't be fixed without pulling the engine and rebuilding from the block.
 

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Discussion Starter · #15 ·
the knock sensor is a little more involved than that.
it is a sensor that detects knock, however its not there to tell you that your engine is old. It works in conjunction with the other systems regulating fuel delivery and timing. The knock sensor was designed to allow different grades of fuel to be run and to adjust timing as your 02 sensors etc wear so that the engine doesn't knock. If you rebuilt your engine just because the knock sensor flagged then you probably wasted money you didn't have to. However, you did end up with a new engine which probably replaced whatever part was malfunctioning causing the knock sensor to flag. Also, as previously stated, the knock sensor DOES NOT CAUSE THE CEL TO TURN ON. It only shows if you plug the OBDII scanner in to scan it, and it usually shows in conjunction with another code. In my case, more than likely the issue is a worn o2 sensor, or the grounding TSB for the 96-98 pathfinder. I will replace these first and then re-evaluate if necessary.
I am quite sure that the issue is not the engine as I had a full diagnostic done on it when I bought including the compression which still tests like new.
 

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Ochono, you are one of the morons who go through life guessing instead of finding out the answers(AKA- being full of shlt). which is ok if you just guess on all your stuff and screw that up. But when other people have problems and ask for help, just say "i dont know" if you dont know the answer. You dont help by making uneducated assumptions. I swear, some people talk just to hear themselves speak. In this case it would have been more appropriate just to not have even replyed to his question at all. This is an overall problem with the internet, some good information and a whole lot of B.S. . Im pretty sure this has to do with morons having internet access.
 

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That being said, I too have recently bought a pathfinder (a 99) and in the first week got 2 o2 sensor warnings along with the knock sensor warning. I went to Advance Auto and got the Hanes book on the car and the o2 sensors look very easy to replace but the knock sensor is a little more work. To reach it you must remove the intake manifold. After that all you do is remove one bolt, unhook the electrical connector and replace the part.
 

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Also, here is some info on the knock sensor. "the knock sensor detects abnormal vibration (spark knock or pinging) in the engine. the knock control system is designed to reduce spark knock during periods of heavy detonation. this allows the engine to use maximum spark advance to improve driveability. knock sensors produce an AC output voltage which increases with the severity of the knock. the signal is fed to the PCM and the timing is adjusted to compensate for the severe detonation. On 4 cylinder models the sensor is located on the side of the engine block below the intake manifold. on 6 cylinder models it is located in the middle of the engine block, underneath the intake manifold." I Paraphrased this from the Hanes manual. See how much better that is than guessing ochno? Retard.
 

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the knock sensor is a little more involved than that.
it is a sensor that detects knock, however its not there to tell you that your engine is old. It works in conjunction with the other systems regulating fuel delivery and timing. The knock sensor was designed to allow different grades of fuel to be run and to adjust timing as your 02 sensors etc wear so that the engine doesn't knock. If you rebuilt your engine just because the knock sensor flagged then you probably wasted money you didn't have to. However, you did end up with a new engine which probably replaced whatever part was malfunctioning causing the knock sensor to flag. Also, as previously stated, the knock sensor DOES NOT CAUSE THE CEL TO TURN ON. It only shows if you plug the OBDII scanner in to scan it, and it usually shows in conjunction with another code. In my case, more than likely the issue is a worn o2 sensor, or the grounding TSB for the 96-98 pathfinder. I will replace these first and then re-evaluate if necessary.
I am quite sure that the issue is not the engine as I had a full diagnostic done on it when I bought including the compression which still tests like new.
i didn't f^king say i rebuilt the engine because there was a knock sensor code.

maybe you pretensious pricks need to read better.

no kidding, the knock sensor helps fine tune the engine... i f^king said that as well.
but if you've got an engine that has 230,000 f^king miles on it, if you change out a damn knock sensor, the engine is still going to have problems.

you can play with your sensors all freaking day long, if you've got a crappy engine, they'll just keep messing up. if you're trying to have a freaking perfect engine, then try buying a new one instead of fiddling with some [email protected] pos. when you only halfass a job, (for you anal guys: only switch out the sensor that was on the ecu codes), then the other older components are going to take up the slack of that brand new sensor...

visa vi... you put in a brand new part, the other parts have more strain.

similar to when you guys switch out your VC gasket and not your PCV, and wonder why your oil pan and crankseals leak more afterwards.

YEAH, a knock sensor detects PINGS! IN THE ENGINE!, what originally causes the friggen pings?? hmmm.... old valvesprings?, old shims?, old cams and timing chains clicking on the inside transferring the sounds thoughout the engine?, maybe even old pistonrod bearings when some prick oilstarved the engine for a few minutes?
YEAH, a knock sensor helps fine tune the engine with the other components..
but fine tuning only does so much when you're dealing with leaking vacuum lines, or maybe bad diaphram valves, or maybe loose intake parts, or maybe old friggen sensors that someone dropped a wrench on 10 years ago, or maybe corroded wires and connections causing a higher Ohms in the system causing things to not work properly.

WHAT I MEANT BY REBUILDING A FRIGGEN ENGINE WAS THAT WHEN YOU START WITH A NEW ENGINE, THE FRIGGEN SENSORS THAT ARE STILL GOOD AND THE HARNESSES THAT ARE STILL GOOD (TAKING INTO ACCOUNT YOU WEREN'T A LAZY ASS AND TESTED ALL THE SENSORS/RELAYS/SOLENOIDS AROUND THE ENGINE WHILE THE ENGINE WAS OUT OF THE CAR AND APART) WILL GENERALLY WORK MORE EFFICIENT...

VERSUS JUST CHANGING OUT THE ONE SENSOR THAT'S ACTING UP, FOOLISHLY HOPING THAT THAT WILL SOLVE ALL THE PROBLEMS ON A F^KING ENGINE THAT'S 16-17 YEARS OLD.

before you act like an ass, try reading a little better. not skimming over a few sentences and then acting like you can figure out my lifepatterns by it.
freaking typical of know-it-all pricks that learned everything from a damn book or from daddy.
 

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That being said, I too have recently bought a pathfinder (a 99) and in the first week got 2 o2 sensor warnings along with the knock sensor warning. I went to Advance Auto and got the Hanes book on the car and the o2 sensors look very easy to replace but the knock sensor is a little more work. To reach it you must remove the intake manifold. After that all you do is remove one bolt, unhook the electrical connector and replace the part.
which is exactly what i f^king said when it came to replacing the knock sensor...
if you can't reach it, then remove the sh!t in the way.

Also, here is some info on the knock sensor. "the knock sensor detects abnormal vibration (spark knock or pinging) in the engine. the knock control system is designed to reduce spark knock during periods of heavy detonation. this allows the engine to use maximum spark advance to improve driveability. knock sensors produce an AC output voltage which increases with the severity of the knock. the signal is fed to the PCM and the timing is adjusted to compensate for the severe detonation. On 4 cylinder models the sensor is located on the side of the engine block below the intake manifold. on 6 cylinder models it is located in the middle of the engine block, underneath the intake manifold." I Paraphrased this from the Hanes manual. See how much better that is than guessing ochno? Retard.
yet again, EXACTLY WHAT I F^KING SAID AND MEANT.
if you're too f^king ignorant to find the knock sensor without consulting a goddamn book then you're too f^king ignorant to being working on cars.
just the name "Knock Sensor" (when i first heard of one..) told me this:
it detect knocks and sounds in the engine... which only comes from a limited amount of sh!t inside the engine block (BECAUSE IT'S POSITIONED ON THE DAMN BLOCK) but anyone with a brain would realize that an extremely loud knocking noise coming from the Head would transfer the noise down into the block also...

but a NEW ENGINE!!!, catch that part?, would not do that... so the knock sensor can ONLY BE MEANT FOR ONE THING... the detonation.

hmmm... when i was 18, i GUESSED right off the bat, what it probably took you 3 hours to read out of a book.

MAYBE IF SH!THEADS LIKE YOU LEARNED HOW TO READ CONTEXT CLUES INSTEAD OF NEEDING A MANUAL OR A SHOPTECH TO SPELL IT OUT IN EXACTING, TIMECONSUMING, SENTENCES... THEN YOU MIGHT NOT NEED SO MUCH HELP IN THE FIRST PLACE.

AND IF YOU EMAIL ME AGAIN, ACTING LIKE AN @SS BEFORE YOU EVEN TRY ACTUALLY READING THE WHOLE POST AND TRYING TO GAIN THE MEANING BEFORE ASSUMING SOME BULLs!!t, I'M GOING TO REPORT YOU. YOU'RE THE SAME TYPE OF [email protected]$ THAT NEEDED SOMEONE TO TEACH YOU HOW TO DRIVE A STANDARD.

i taught myself... as well as double clutching, drifting, racing w/ apexes, and every F^(K!NG thing under the hood.

so who's the retard? get some grease under you nails and posts under your belt before you start acting like a prick. then you might have an excuse. i do, and i don't act that annoyingly spoiled.
 
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