I just got a P0139 engine code on my 97 Maxima SE with 126k miles on it. The code description states that, "It takes more time for the sensor to respond between rich and lean than the specified time." I am assuming that I have a bad, rear (post-cat) oxygen sensor. I found one of those China made heated, four wire universal oxygen at an incredible price of $24 shipped on Ebay (shipped from USA). Is there a guide on how to match harness wires to the sensor? I also have a 2002 I35 with a bad rear oxygen sensor (P0051) and I assuming that this sensor will also be compatible, right? Ebay link to the sensor is below.

http://cgi.ebay.com/ebaymotors/OXYGE...ht_1800wt_1165

 

hey man here is a guy i got my O2 sensors from. hes good people and the sensors work good and they are less then the other ones your looking at.
http://shop.ebay.com/evalero1/m.html...dkw=&_osacat=0

As for them being compatible yes they are.

 

"It takes more time for the sensor to respond between rich and lean than the specified time"

This is absolutely a font O2 sensor. The rear O2 sensor sees no fuel what so ever if your catalytic converter is working fine.
And, there is no P0129, I assume you meant P0159 (P0159 02 Sensor Circuit Slow Response (Bank 2 Sensor 2)). This should even tell you which sensor you need to look at.