Nissan Forum - Nissan Enthusiast Forums - 200 Quest. What does it all mean?

Hello:

I am new to the workings of the Quest, but have some issues that I would like to confirm are all connected.

The problem:

1. The speedometer. It works fine, but when in stop & go traffic, it will stop working (after bouncing a little). It will cease to work until the engine is turned off & on, or sometimes I rev the engine hard, or get back on the open freeway for a while.

Also: My wife says the odometer stops turning at those times also, but I have not witnessed that myself.

Now, the first thing I hear is that I need to change the Vehicle Speed Sensor, but before I do, I wanted to get direct feedback on the following:

2. When the engine starts from cold, I get a malfunction light in the form of the "O/D Off" blinking for about 8 seconds. The manual says this is a sign of transmission trouble. However, every subsequent time the engine is turned on in that day, it no longer gives that warning.

3. I hooked up a OBDII code reader and received the P0325 error, which says the Knock sensor is bad.

So, should I focus on the knock sensor, or keep my focus on the Speed sensor? Or is there something else I am missing? Could these be two or three separate problems? Too coincidental in my opinion.

Lastly, if it is a Speed Sensor issue, I now have the stupid question of the day: Where is it? I have a Haynes manual and they show a somewhat close up of it, but I cannot tell where it is, not to mention their photos don't always show what it looks like with everything else around it. I think it is in the back, right side of the engine compartment (looking down), but I do not see the item as it looks in the photo.

I do have some experience working on other makes of cars. This is my first time delving into the Nissan.

Any help is much appreciated.