So I was driving the other day and my CEL came on. I checked the codes and I got 03 13 and 05 10. I checked my haynes manual and both codes are listed as "downstream oxygen sensor maximum voltage monitor fault". These codes have come on before and gone away. I have a cali spec and the haynes manual doesn't cover anything on it. And I don't know anything about oxygen sensors so I have know idea what this means and i couldn't figure it out in the manual. Are my sensors dead? Will it just go away again? And how do I know which downstream sensor is messed up since it doesn't specify. I'm really stumped here. uh, sometimes I really hate having a cali spec.

 

You should probably replace the sensor, the codes keep popping up because it's readings are going out of the acceptable range. On the Cali Spec 99, there are two downstream O2's which monitor the pre-cats. The trick here is to figure out which one is acting up.

Maybe somebody with a factory service manual can pin down the correct sensor from the codes your getting.

 

I had the same codes on my MAX. After an extensive research about Cal emmisions I can say that I know everything about these damn O2 sensors.

Since mine had 115k miles I replaced all 4 sensors ($377 ordered on-line).
Code 5-10, P0138 downstream O2 sensor RIGHT bank (white insulation color)
Code 3-13, P0158 downstream O2 sensor LEFT bank (red insulation color)

When you look at your engine bay you will see 4 connectors next to the left bank aluminum cover ("V6 3000 Twin Cam Valve..."). The ones that you need to replace are the middle ones.

Sensors Bosch OEM p/n:
-upstream sensor left bank (or front) - 13948 (3 wires with light blue insulation)
-downstream sensor left bank - 13348 (4 wires with red insulation)
-upstream sensor right bank (or rear) - 13505 (3 wires with white insulation)
-downstream sensor right bank - 13374 (4 wires with white insulation).

None of the rear sensors have the plastic cap and seal next to the connector (like the non-Cal) and all the connectors come into the engine bay.

Let me know if you need more info.

BTW, download the Nissan Factory Service Manuals (1994-2002) (500MB) for free from
http://www.benddatacenter.com/nfsm.zip

Good luck.