Rear o2 Sensor

[-ToM-]

hey guys, my o2 sensor sometimes gives me a check engine light, but sometimes it doesnt, should i be concerned, or no. Should i replace it, and if so how do costs range for that. And if not what kind of risks to i take.

[Zuluwun]

IIRC, the rear O2 sensor is really just there to monitor the cat's performance. Have you pulled the code of the CEL?

[baymoe]

I think I've been having the same issue for the last 3 weeks. Seems as though the car is consuming quite a bit more gas. My guess would be in the range of 15-20% more gas for the same mileage driven.

[Zuluwun]

^ Had that kind of consumption when my front O2 sensor died. Pull codes, it's the only way to know for sure.

[Cosmo77]

IIRC, the rear O2 sensor is really just there to monitor the cat's performance. Have you pulled the code of the CEL?

Yes the rear o2 sensor is there to monitor, but it also has a huge amount of input into the long fuel trim performance and will cause sometimes drastic changes in fuel mielage.

[Zuluwun]

^ oh, good to know. nice having a tech around at times like these, thanks Cosmo.

[baymoe]

I'm a little stunned how much those oxygen sensors when Joe at MoT got the price for me.

[-ToM-]

the code is Po138 - which when i looked up is the rear o2 sensor, they're really expensive tho, and honestly i get a cel like maybe 4 times a month not often

[nuttygent]

Easy to access the sensor when the car is jacked up at front. Bought a Bosch universal at a parts place for $85, maybe 2 hours and no more CEL.

[MyRxBad]

Easy to access the sensor when the car is jacked up at front. Bought a Bosch universal at a parts place for $85, maybe 2 hours and no more CEL.

Where did you pickup your o2 sensor from?

[TheMAN]

universal O2 sensors cause more problems than good
you have to splice the new sensor into the old sensor's wires... and the splices might not be good, and even if they did, they won't last long from salt spray and stuff like that

get a direct fit NGK or Denso O2 sensor!