So I got these two diagnostic codes today, read up on them in my Haynes manual but I was looking for a more generalized explanation

0707 Downstream Oxygen sensor or circuit fallout

0510 Downstream Oxygen sensor maximum voltage monitor fallout

From what I have read the downstream sensor has no effect on the PCM air/fuel ratio. The rear sensor should produce a lower voltage due to the lower amount of oxygen present at that point.

I am guessing that there may be a bad connection since there is a signal problem.

Since I have a DTC it is now running on an open loop fuel control.

What I am a not fully understanding is the troubleshooting from this point.

Any info would be great!

 

if you have a multi meter you can read and see if the sensor is outputing the amount it should be, since you got a code for that sensor, it seems as though its faulty and you'll need to replace it? are you trying to diagnost and make sure that its truely bad or that is really is bad?

Correct me if I'm wrong but I thought the rear o2 plays a less important roll once car is warmed up, but until then is just as important as the other 2 o2?

 

youre right about the warming up part partially. The car does not use any O2 sensors until 600F is reached. And the rear o2 sensor is not as important as the front ones.

 

its jsut like the pre-cats in a stock y-pipe....useless after main cat is hot

 

You think you have rear o2 problems! Check out this guy!

http://forums.maxima.org/showthread.php?t=363241

 

ha thats certainly bigger than my problem