1996 Nissan Maxima 2.5 V6 Engine Knock sensor The engine runs fine; but it sets off 2 codes knock sensor & ignition. Just this week had the plug wire and knock sensor changed, new. Still the same code light comes on. I appreciate any and all help thanks.

P0325 NISSAN - Knock Sensor Circuit Malfunction
Possible causes- Faulty knock sensor
- Knock sensor circuit short to ground
- Knock sensor circuit short to power
- Knock sensor circuit open
- Faulty Engine Control Module (ECM)

Read more: http://engine-codes.com/p0325_nissan.html#ixzz29K4BM3th

Hi Thomas,
We have a couple different issues here.
First, your Maxima is either NOT a 1995 model, or it is a very late 1995 model that "thinks" it's a 1996. The reason I say this is because a 1995 model Maxima is NOT OBD compatible and is not capable of outputting "P-codes" to a generic OBD scanner.
Those Nissans that were claimed to be OBD compatible in the late 1995 model year only output certain codes. To find out the rest of the story, you still need a scanner that has software capable of accessing the engine computer through the Nissan-2 connector (usually in the fuse block area).
Then you need to understand about Diagnostic Trouble Code (DTC) P0325.
This code does not necessarily mean that you need a new knock sensor. I think you will be a little less confused if you know the facts. What you need to know about ALL fault codes is that they NEVER tell you what parts to replace. Fault codes only tell you that the computer has a problem with one of the many circuits and systems that it monitors. The fault code will tell you which system is failing or which circuit is failing. They DO NOT tell you what is wrong with the circuit or system that it is reporting. The person diagnosing the vehicle is supposed to figure that one out.
Most people think that "diagnostics" means plug in the "magic box" and replace everything the computer tells you to replace. I WISH it was that easy!
Now that you know all of this, we can examine the code itself. What causes this code to set? ...I'm glad you asked. The computer controls the ignition timing in your car. The trick is to advance the timing as far as possible (for more power and efficiency) while not advancing it too far, which will cause pre-detonation (also known as "ignition ping"). Pre-detonation can cause serious engine damage, including burning holes through a piston.
Here is where the knock sensor comes in.
SCENARIO 1: The computer advances the ignition until the knock sensor "hears" an ignition ping. When this happens, the knock sensor sends a signal to the PCM to let it know that the engine is "knocking". So the computer responds by retarding the timing a little to stop the knock. When the knock stops, the knock sensor will stop sending a knock signal to the computer.
DTC P0325 sets when the computer has ******** the ignition timing as far as it possibly can and the knock sensor is STILL sending a knock signal.
SCENARIO 2: The computer also tests the knock sensor by deliberately advancing the timing too far for a few seconds to see if it gets a signal from the knock sensor.
So, P0325 can also set if there is NO signal from the knock sensor when the computer is EXPECTING a signal.
For scenario 1, the cause is usually a mechanical knock in the engine. Loose timing belts, worn/loose timing chains worn distributor shafts, bad pulley bearings, etc. The knock sensor does not know the difference between a knock caused by pre-detonation and a knock caused by a loose valve lifter (or other mechanical reason). The knock does not go away when the timing is ******** because the knock is not CAUSED by timing....code P0325 sets.
For scenario 2, the cause is usually either the knock sensor itself or a problem with the wire between the knock sensor and the computer or the knock sensor is not grounded properly. These things will cause the knock sensor to not be able to get a message through to the computer....code P0325 sets.
Now, the misfire at idle is a whole other issue. The computer will default to base ignition timing settings if there is a knock sensor fault. You may notice a little loss of performance, particularly during heavy acceleration, but there is NO WAY that your knock sensor is the CAUSE of ANY misfire - especially not at idle. However, it is VERY possible that whatever is causing the misfire could also be the cause of the knock sensor code.
Basically what I am saying here is that you need to put the knock sensor problem "on the back burner" until you find out what is causing your misfire. Unfortunately, misfires can be cause by a LOT of different things ranging from a bad spark plug to a cracked cylinder head or worn-out piston rings. The misfire simply has to be diagnosed using the proper procedures to avoid replacing a bunch of things that will not fix the problem.
With all that said, WHEW! I hope you got through all that!
The older Nissans are notorious for the distributor shaft bushing going bad and causing a loud "rattling" noise. The movement of the shaft can cause a cylinder misfire, and the rattling can cause a knock sensor code to set. I have fixed many of the Nissan V-6 engines with this same problem by replacing the distributor. This is the FIRST place I would look. If your distributor is not rattling, try revving the motor just a little and see if it rattles. If it does, replace it. If it does not, let me know and we will look elsewhere for the cause of your problem.
-Dave (dttech)

A knock sensor tells the engine computer when one or more of your engine's cylinders are "knocking", that is, exploding the air/fuel mixture in a way that delivers less power and can be damaging to the engine if prolonged. The computer uses this information to tune the engine so that it doesn't knock. If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine. Knock sensors generally bolt into or thread into the engine block.

This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.

Symptoms: You may notice drivability problems including a lack of power and perhaps some hesitation. There may also be other symptoms.

Causes: A code P0325 most likely means one or more of the following has happened:
* The knock sensor is faulty and needs to be replaced
* There is a wiring short/fault in the knock sensor circuit

Possible Solutions
* Check the resistance of the knock sensor (compare it to factory specs)
* Check for broken/frayed wires leading to the sensor
* Replace the knock sensor


Test it and tell us news.

A Bad Knock Sensor will not cause a misfire, unless the advance is off due to a faulty Knock Sensor. The O2 Sensor will cause a random misfire.

Good luck on this repair.

First, I would like to mention that most knock sensor codes are not caused by the knock sensors, but a mechanical problem with the engine. The knock sensors cannot differentiate between noises caused by mechanical problems like a bad pulley bearing, bad motor mount, noisy alternator bearings, etc. and spark knock. knock sensor codes are set when the computer has retarded the timing as far as possible to compensate for ignition ping (Spark Knock) and the noise still exists.

With that said, here are the instructions.

Remove the Intake Chamber assembly.
Disconnect Injector connectors.
Disconnect the heater hose from the Intake Manifold.
Remove the 9 bolts. 2 nuts, 2 plate washers and Intake Manifold assembly.
Remove right hand engine mounting stay and water outlet.
Disconnect the following hoses and connectors:
Radiator inlet hose.
Engine coolant reservoir hose.
Engine Coolant Temperature Sensor connector.
Engine Coolant Temperature Switch connector.
Ground strap connector.

Remove the 3 bolts and right hand mounting stay.
Remove the wire band.
Disconnect the water bypass hose from the inlet housing.
Remove the 2 bolts, 2 nuts, 2 plate washers and water outlet.
Remove the 2 gaskets.
Disconnect the Knock Sensor connectors.
Remove the Knock Sensors.

P0325 is a knock sensor. the knock sensor will not set the ses ligth

If the car is pinging you will set a knock sensor code.'
This comes from bad gas and running lean., You really need this professionally inspected to rule out the basics. I have seen alot of nissans with the knock sensor code stored but the light is still off.
Fill up the tank with high octane chevron and some techron injector cleaner and clear the light. If it stays off for a couple days then go get it inspected. Even if the code is stored it will still pass as long as the light is still off and the monitors have run.

mate check your timing.it could too advance bro.have that checked and i think it should be allright

The Crankshaft Position Sensor is located: Under hood, driver side, front engine area, mounted rear of crankshaft pulley
The Knock Sensor is located: Under hood, center, front engine area, below intake manifold, mounted on block