# Knock Sensor Question / 1999 Maxima



## Phil Wages (Oct 11, 2007)

I just purchased a 1999 Maxima SE for my daughters first car. The Service Engine Light recently came on and the codes were a bad knock sensor and bad rear o2 sensor. I changed the rear o2 sensor, reset the codes, and the service engine light has remained off. The knock sensor code would not reset.
My question is:
1. How can I tell if the knock sensor is bad since I have read that the o2 sensor could have caused the fault with the knock sensor?
I would appreciate any help you can give me as I want to ensure the car is safe for my daughter.


----------



## Jeff (Oct 17, 2002)

How did you reset the code?

Is the car acting 'strange'?...i.e. bad gas mileage, stumbling...etc


----------



## Phil Wages (Oct 11, 2007)

Thanks you very much for your reply. I have a mechanic friend who reset it with the same machine that diagnosed the codes.
The car is not stumbling, does not have a poor idle and the gas mileage seems about right. The car seems to be running fine, however, I have had it only a short period of time. Perhaps it could run better, but the way it is performing now seems darn good.


----------



## nafddur (Oct 19, 2007)

In my experience with a 95 SE (that I've had for over 13 years and is now approaching 190K miles), the knock sensoris set off by many other things. In fact, I've never seen the knock sensor code alone when I've had check engine problems.

Fixing what ever other problem set off the check engine light has always cured the knock sensor problem for me as well. If the light remains off, you no longer have a problem.

Of course, I'm assuming your 99 behaves as my 95 does in this regard!


----------

