# knock sensor



## bidroc (Sep 15, 2010)

Does anyone know how to get to the knock sensor on 95 200sx SER 2.0? I tried getting under the car and it seems like its too high up under the intake to reach. Do I need to remove the intake to replace it? 

Also, once I put a new one on, will it automatically reset the timing back to factory?


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## ChrisAce (Sep 30, 2004)

I am pretty sure the O2 sensor is on top of the exaust manifold near the front of the engine. Unless for some reason your 95 is any different than my 96. It should be really easy to get to. Don't forget to use copper anti seize when installing the new sensor. it should come with a small tube.


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## rogoman (Dec 16, 2004)

bidroc said:


> Does anyone know how to get to the knock sensor on 95 200sx SER 2.0? I tried getting under the car and it seems like its too high up under the intake to reach. Do I need to remove the intake to replace it?
> 
> Also, once I put a new one on, will it automatically reset the timing back to factory?


Try using a 3/8" drive long extension with a universal joint. If that doesn't work, you'll have to remove the intake.

If the old knock sensor caused the ignition timing to be constantly retarded, then the new one will allow the ECU to set the timing back to factory spec.


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## ChrisAce (Sep 30, 2004)

Haha! Silly me! I'll bet you guys were wondering why I was talking about the O2 sensor? Well, I am too. I think I got this thread confused with another one. Which one? I am not sure of that either. Any hospitals nearby?

For mine I removed the bracket that covers the starter motor first. It is a $&%*# to get at let me tell you. Actually, removing is easy enough with just an open end wrench. Installing it is another issue. It helps if one of your arms is long enough to reach out from under the car and around the front quarter panel back into the engine compartment and under the intake manifold. Basically it would need to be about 13 feet long and have 6 joints. Good luck on that one.

Have you really narrowed it down to the knock sensor? Have you checked the resistance first? It should measure 500-620 K ohms with the engine cooled down. I can email you the excerpt from the service manual.

Make sure there isnt an actual knock first. I had a knock sensor code thrown, which by the way does not turn on the light so it will still pass emmissions. I had an actual slight engine knock, usually caused by lean mixture. I replaced the fuel filter, which is a lot cheaper and easier to get to, then the knock went away. Problem solved.


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## DjSpeed247 (Apr 13, 2009)

Hey guys I need to change My sensor too. what size is the bolt on the sensor? and is that the only way to get to it?


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