Thread: O2 sensor keeps dying

What makes you think they are dying? Because my AFR goes everywhere and the car starts hesitating and doesn't accelerate, replace sensor and problem solved.

Have you pulled any DTC codes from the ECU? No I haven't, how do I get codes from the ECU?

Where is the sensor situated in the pipe.
Exactly as this one,



I'd say it's like 1 or 2 o'clock looking from the back to the front of the car.

Are you using any fuel additives? No fuel additives

Is the sensor circuit open or shorted (harness issue)? The sensor was giving a correct measure, not sure what you mean by shorted or open.

Have you monitored the new sensors for proper voltage fluctuation with the Nismotronic software? Have you datalogged the o2 sensor? I haven't datalogged it. Will do and then post what I get.

Thanks

Sorry for the late reply.

The placement of the sensor (in the pipe) is fine. To be honest, I am not too familiar with Nismotronic ECU's, having never had one myself (I require OBD2), but I know you can log the DTC's (diagnostic trouble codes) with the program's software. @JKTUNING would be of more help with that. You should see code 33 (3,3), for o2 sensor/heated o2 malfunction.

When I suggested the sensor curcuit might be shorted or opened, I was inferring that there might be a break in the harness wiring somewhere. This might cause a grounding issue or similar, causing the sensor to malfunction. I see that you are not running the NB o2 in the primary section of the exhaust manifold, did you have to extend the wires in order to run the NB sensor so far from it's original location? If so, there may be an issue with the wiring there. If there isn't a proper connection to the heater wire (ECU pin 111), this would cause premature failure of the o2 sensor for lack of heater function. Whether you have extended the harness or not, I would check the heater wire (power supply) on the sensor plug.

As far as disabling o2 feedback and tuning just off the fuel map (as others have mentioned), this is definitely a good option. I know that even with an OBD2 Calum RT ECU, I was able to have a stable and consistent A/F ratio when I drove around with the o2 feedback disabled. With the Calum ECU, I simply disabled the o2 feedback flag and just ran off the fuel maps. I would assume that disabling o2 feedback with Nismotronic is very similar, if not the same.

As far as why the sensor keeps failing, I can only think of two reasons: the sensor circuit is open/shorted (harness issue I mentioned before) or for some reason, the heater pad function (in the sensor) is not working from lack of power supply, which is causing the sensor to get fouled. (Location = ECU pin 111 or middle harness pin on o2 sensor plug)

Not sure if any of this helps or not but hopefully it does.

What version of the NismoTronic software are you running?

I would suggest upgrading to the NismoTronicSA software and using your wideband for closed loop, like previously suggested.

Honestly, if you get the tune dial in pretty well .. it might benefit you to just keep it in open loop after you are done tuning.

Yes, the O2 wiring was extended to reach out in the current location, so it maybe related to a circuit issue. I've disabled the O2 feedback and I'm running straight from the fuel map, it running a little rich right now but nothing apart from that.

Thanks for your suggestions!

I'm running the latest RT software and I'll probably upgrade to SA in the following days, I need to redo my fuel/timing since I've just upgraded to kelford 184c, S/R and adj cam gears.

Would it be best to just start from scratch or import my current tune into SA?

You really can't import your fuel/timing tables from RT into SA, so honestly it would be best to start from scratch.

The RT version will not be getting any additional releases/support since the SA is the newest version now.