i have a 1996 Nissan 300zx Non Turbo. If you are getting this error on your z, YOU ARE IN BIG TROUBLE

Note: although my car is a Nissan, the idea is basically the same. In your car, the knock sensor location could be more easily accessible, therefore, this repair can take much less time for you.

replacing this little part is difficult.

this week I went to the smog check station and I didn't pass the emissions test. when I connected my OBD2 (OBDII) reader, I said:

Knock Sensor 1
Circuit Malfunction
Bank 1 or 1 Sensor

why do I say you are in trouble. well my friend because its gonna take you at least $2000 dollars to have it replaced if you have it done at a shop. or if you do it yourself, it will take you a week to do it, plus the knock sensor is not cheap. I went to the local auto parts store and it cost me 189$ dollars, about 200 with all the tax and gas I had to waste to go get it.

so if you are wondering how much its gonna cost to fix or replace one of this parts, it will cost a lot.

of course, im not gonna pay 2000 plus, im going to do it myself..

first I had to invest on a code scanner to read the code - $100
1 knock sensor - $200


first im gonna have to remove the intake manifold, this took me about 4 hours to do
300zx manifold

once I have the manifold removed, I have to remove these:

remove radiator

remove radiator intake and outtake housing

remove fan
remove all belts: power steering, alternator and if you have a/c
remove harmonic balancer
remove timing belt covers

remove timing belt

remove intake housing

once you have remove all the above, your engine will look weird, now I took a picture of the stupid knock sensor. are you can see the location of the knock sensor is locate in the engine valley, which you have to remove a lot of crap to get to it.


removing and installing the knock sensor is very not very difficult to do. I took a shop class after I graduate from high school and I love working on my car. but this has got to be one of the most annoying things to fix on my car. why? because all that work for just this little device. I have to uninstall all those components on my car just to get to it. the installation is not very hard, whats difficult is the un-installation, I had to re-install everything when it worked fine. and to make things worst, my check engine light did not show a knock light at all for my knock senor on my car knock, I guess the timing was affected and that's why I didn't pass the test. if it wasn't for the ecu which was the knock detector i've never would have known that the knock censor needed replacing. but the knock valve is so expensive I cant believe I costs so much. lucky I go the knock code because I could hear my engine knock when I was driving.

if you want to take a close look on how this little parts looks like here is a picture I took with my camera. maybe its not a good image, but the pic looks good enough


i dont know if this is going to be the same for the following cars, but I hope its much easier for you to find where it is.

at the end what the main problem was that my car had a coolant leak, and I guess water came in contact with the connectors on the knock sensor and the cable and the leads became corroded therefore the contact could not be made when I tested the and that's why I was getting the error code p0325. but to fix it I had to remove a bunch on things on the engine to get to the sensor itself. here is my finger pointing to where the knock sensor location. it was located under the intake, I wish Nissan had better engineer the location of it to make it easier to replace. but on the other hand they don't usually go bad. my sensor itself test ok, it was just the the connectors were corroded and therefore there was no contact so the computer gave an error and affected the timing and therefore I could not pass the emissions smog test.

if you have any comments or thoughts about this, please let me know.