Got some more codes off my buddies 2000 maxima 3.0.

P0139 seems to be a o2 sensor fault but I also found out there is a difference between CA vehicle and not. How to I did out if his is CA or not? Also which sensor is the one that needs replacing? There is several

P0400, seems to be a problem with the EGR valve, is it the valve itself or does this code pop up on several other issues? Just wanna make sure it's the actual valve before I go replacing parts..

Thanks guys!!

 

Work on the P0400 problem first. It could be causing the P0139 code.

For the P0400, the possible causes are:
* EGR passage clogged
* EGR volume control valve stuck closed
* Harness or connectors (EGR volume control valve circuit is open or shorted.)
* EGR temperature sensor and circuit
* Exhaust gas leaks
* Dead (Weak) battery

The cause is probably one of the first two. The EGR pipe does tend to plug up with carbon and can be cleaned out. You would have to take it off and see. The ERG valve itself is equally a possibility.

Here is a link to the service manual. Start on page 414 to diagnose the P0400:

http://boredmder.com/FSMs/Nissan/Maxima/2000/EC.pdf

To find out if the car is a Fed or Cali car, look at the VIN number. The 12th character from the left will be an N for Canadian, U for Fed or a V for California. Canadian and FED use the same emissions standards.

If the car is Fed spec, the sensor is after (behind) the main catalytic converter.
If the car is Cali spec, the sensor is in the y-pipe, see below photo (approx center).

 

The vin has neither in it? Vin as follows

JN1CA31A0YT220819

 

These VIN #'s don't hold emissions related info. Easiest way to tell is look at the front of the engine:

This is what cali spec looks like:


4 sensors = cali
2 sensors = fed

 

My bad. the VIN doesn't have it, it is the ID # that is on a tag attached to the firewall.

 

I checked the front if the engine and it has 2 plugs, so it's a fed.

Just wanting to be 100% sure. It is NOT CA, when I go to get the O2 sensor. Also, it's the sensor directly behind the cat. converter, in above pic would be the very last sensor. Correct?

 

You are correct when you say the sensor is directly behind the catalytic converter, but the above picture is for a California emissions car and you don't want to go by that.

This drawing is a Federal emissions exhaust system: