Hey guys,

Ive got some questions concerning a few codes im getting and need some input. Im getting the codes 0707 (rear heated O2 sensor) and 0510 (which points to issues with the rear 02 sensor). Now this is the sensor that is behind that cat which, if i remember right, are only on the 97-99 models. The purpose of this sensor is to take over if one or both of the upstream sensors fails. Now, my question is, why would i get a code for the back up sensor and not one for one or both of the front sensors? My thoughts were that it could be a bad cat which is why the front to arent affected. My car seems to be running very rich as im putting out large black puffs of smoke upon acceleration after shifts under WOT and my gas mileage doesnt seem to be as good lately.

I also just recently used some Lucas fuel injector cleaner so Im wondering if this might have fouled the sensor in question by dumping all that crap that it cleaned outta the system upstream, a common problem with seafoam. Im not getting the rotten eggs smell that is usually associated with a bad cat either. So my question really is, what should the plan of attack be?

1. run another tank of gas since I put in the injector cleaner and see if the ecu can recognize that the injectors are flowing much more freely and in turn adjust my rich AFR via the front sensors.

2. replace the cat and see if that will change the signal from the rear heated sensor.

3. just replace the rear sensor and see if it just randomly went bad

4. weld a bung in front of the cat and stretch the rear heated sensor to it and say screwwwwwwww you emissions

thanks for any help guys!

Grant

 

There must be a test to confirm if the sensor is bad or good. When I get stuff like this, I have a good mechanic in town that has a $7000 snap-on scan tool, and he knows how to use it. We can easily check the values of each individual sensor, and then go from there. To me it's worth the diagnostic fee, if I can't how to test the sensor with an ohm meter.

 

0707 points to the sensor behind the cat (or for those of us with 95/96, in the cat). I had that code pop up randomly after some extensive highway driving. I replaced the sensor (bought it on oxygensensors.com- best deal I could find) and it has not come back since. This happened about 2 years ago. That sensor is used for reference and does not impact performance or fuel economy. I would replace it, reset the ECU and see what happens.

0510, I can't find that one in the ECU decoder. You're saying that code points to one of the 2 sensors in the front? If so, you should definitely replace it, because those two do impact gas mileage. Cleaning your MAF may help as well.

If you suspect that the cat is clogged, a quick test that I found on here a while ago goes as follows - you can put your hand at your exhaust tip and feel the flow of air. It should be puffing/pulsating somewhat; it shouldn't be a steady flow. If the flow is steady, the cat may be clogged and in need of replacement.

 

I'm getting the same code for my 99 GLE. What worked for you? Thanks.

 

I read that nissan actually doesn't recommend fuel injector cleaners

it's an "improper" cleaning method

 

95/96 have a rear O2 as well. All it does is determine whether or not the converter is functioning properly. It doesn't 'take over' for the front O2s either.

CRiME: 0510 is present for '98 and '99, not '97.

Have you checked your O2 sensors yet? Check them out (all of them, the fronts are probably getting lazy which is contributing to MPG) to see if they're actually bad, or it's wiring, or the converter, etc.

 

Just want to let you guys know that I replaced the rear O2 sensor and the CEL haven't come back after drove it on high way for about 20 minutes. Last time, when I reset the light, it came back after drove it for about 10 minutes.

To remove the O2 sensor, you will need a special O2 sensor tool kit. I rented a set from Autozone. I ordered my O2 sensor from O2sensor.com.