# 97 altima knock sensor code HELP!



## ouch (Jul 30, 2006)

Can anyone please advise this old" backyard " mech. on changing a knock sensor? the ck eng light is on and I cant get it passed NYS inpection. Can this sensor be bad or could something else be triggering this code? . The engine was shaking and missing >about five of these "auto tecks" told me it was every thing from bad gas to a cloged injector to the car needing a valve job!. After going over the car my self (because I cant afford these auto Doctors) I wipped out my trusty can of wd 40 and sprayed the vacum lines and intake manifold and found a leak in the intake gasket. ( I pay attention to the old timers who cant even send a email) I changed the gasket and wa la the car runs like it just rolled out of the show room! But the chk eng light is still ON after clearing the codes. The last guy at Auto Zone tells me its ABSOLUTLY the knock sensor. What do you think ? Change it ? if so where the heck is this thing? 

Thanks for any Help


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## MickeyKnox (Jun 17, 2006)

why did you use WD40? weird. buy throttle cleaner to clean throttle body.

buy a substance that will clean your exhaust system. ask in autozone.
don't just spray WD 40 in your gas tank.

are your mounts alright? my knock sensor was on for a while. I cleaned exhaust system with
that special substance, changed motor mounts and it was gone.
but maybe your chain guide is broken and causing the engine to knock --> knock sensor
light is on.

I never heard of anyone replacing knock sensor.


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## LONDONDERRY (May 19, 2004)

ouch said:


> Can anyone please advise this old" backyard " mech. on changing a knock sensor? the ck eng light is on and I cant get it passed NYS inpection. Can this sensor be bad or could something else be triggering this code? . The engine was shaking and missing >about five of these "auto tecks" told me it was every thing from bad gas to a cloged injector to the car needing a valve job!. After going over the car my self (because I cant afford these auto Doctors) I wipped out my trusty can of wd 40 and sprayed the vacum lines and intake manifold and found a leak in the intake gasket. ( I pay attention to the old timers who cant even send a email) I changed the gasket and wa la the car runs like it just rolled out of the show room! But the chk eng light is still ON after clearing the codes. The last guy at Auto Zone tells me its ABSOLUTLY the knock sensor. What do you think ? Change it ? if so where the heck is this thing?
> 
> Thanks for any Help



Good diag with your Altima.
If you attempted to clear out the codes and the CEL is still on, then there might sill be a code in there. To make sure, reset the ECU manually again, if it still come on then you have a stored code, find out what it is. In general if the knock sensor is tripping then something else is going on. If not then yes you might have a bad knock sensor, which is located under the car, close to the oil filter.


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## ouch (Jul 30, 2006)

MickeyKnox said:


> why did you use WD40? weird. buy throttle cleaner to clean throttle body.
> 
> buy a substance that will clean your exhaust system. ask in autozone.
> don't just spray WD 40 in your gas tank.
> ...


 I did not spray wd40 in the tank, only on the intake manifold. other than the check engine light the engine runs fine .


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## ouch (Jul 30, 2006)

When I removed the knock sensor I found a hair line crack in it from where the bolt head sits all the way down the side. Does this definitely mean it is bad or do you think it takes more than that to render it broken ?


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## LONDONDERRY (May 19, 2004)

ouch said:


> When I removed the knock sensor I found a hair line crack in it from where the bolt head sits all the way down the side. Does this definitely mean it is bad or do you think it takes more than that to render it broken ?



It could mean its bad. I would replace it so to take that out of the equation of what might be wrong with your Altima. Reset the ECU once you installed it.


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## MickeyKnox (Jun 17, 2006)

LONDONDERRY said:


> It could mean its bad. I would replace it so to take that out of the equation of what might be wrong with your Altima. Reset the ECU once you installed it.


isn't it like 300$ per knock sensor?
what if you don't replace it. it's just a sensor it would't hurt the 
performance. isn't it like rear O2 sensor. you can ignore it.

I am just asking if it's ok to ignore knock sensor in case mine goes bad.


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## MickeyKnox (Jun 17, 2006)

found very interesting read about knock sensor/overheating. etc
http://www.federal-mogul.com/fmeconnect/technicalservices/downloads/1422.pdf

this is a GM cars literature. is there anything similar about nissans.
it's very concise and has lot's of useful information for me.


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