I am getting code 0510 set, which says the "right rear heated O2 sensor Max voltage is too low". I had the code once 4 weeks ago, reset it, and now it is back again. Does anyone know if this code means that the sensor is not working correctly, or does it point to something else? I think the sensor is supposed to fluctuate around .45V, and the ECM tries to adjust the injector pulses to maintain that ideal .45V (above .45V means lean it out, below .45V means richen it). Maybe "Max voltage too low" means that the thing is drifting, and sometimes is not able to hit some upper limit that the ECM thinks it normally should? The car runs fine, mileage is about 24.5 MPG (combined), which is where it always has been... I have 57K miles on the car, which seems a little soon to be replacing an O2 sensor, so I want to be sure before I shotgun in a new one...

 

just replace it...I have been getting the same and need to just buckle down and buy it...but there are so many other more exciting ways to spend a hundred dollars...

 

I replaced my rear o2 around 55,000 miles. Samething code 0510, reset and a few weeks later back on again. After a few months of this I just went ahead and replaced it. Been 6 months now and no more codes. Purchased sensor from Courtesy Nissan, $65 which included shipping. Sensor easy to replace with the special 02 socket, free rental from autozone.

 

Thanks, I'll order the thing and replace it the next time the code pops up - I have the special socket already, bought for use with my last car...