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Louis138
Louis138, Nissan Technician
Category: Nissan
Satisfied Customers: 32
Experience:  Have maintained, repaired, and owned Nissan vehicles dating back to 1985.
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2003 NISSAN XTERRA 4WD V6 3.3L SFI, KNOCK SENSOR -WHAT IS IT

Customer Question

2003 NISSAN XTERRA 4WD V6 3.3L SFI, KNOCK SENSOR -WHAT IS IT ,WHAT DOES IT DO,WHERE IS IT LOCATED,WHY DOES IT GO BAD.HAVE CODE PO328 KNOCK SENSOR 1 CIRCUIT HIGH OUTPUT ,BANK 1 OR 1 SENSOR 1 CIRCUIT HIGH OUTPUT BANK 1 WHAT IS THIS??
Submitted: 8 years ago.
Category: Nissan
Expert:  Louis138 replied 8 years ago.
The knock sensor is a pezioelectric sensor mounted on the engine that the computer uses as a microphone to "listen" for predetonation and retard or advance ignition timing and/or richen/lean the fuel mixture accordingly. They are known to go bad on these engines, and when they do the computer cannot sense knocking, so it just guesses on the safe side of its parameters, which wastes some fuel. The computer generates a code that it stores when they go bad, but the "check engine" light will not come on just for that.
The knock sensor is mounted under the intake manifold, on top of the engine in the middle. It is a black plastic sensor, approx. 1" in diameter, with a 2 wire harness coming off of it. It is difficult to get to, since the intake manifold has to come off. An easier way to replace it is to just splice a new sensor and pigtail on and mount it on top of the intake manifold. Just leave the bad sensor down there. There are detailed instructions and pictures here: http://tunfs.yuku.com/topic/363/t/Knock-Sensor-Relocate-2002-Fronty-ODB2-code-P0328-or-PO327.html
Try replacing the knock sensor, then clear all of your trouble codes and drive for a few days like normal and see if any other codes show up.

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