Hi All,
Just replaced the upstream O2 sensor on our 2012 Forester (150k miles), due to the following codes:
They were kicking on the Check Engine and Traction Control lights, and flashing the Cruise light. I also noticed that the O2 B1S1 voltage was reading 0.00 all the time. B1S2 showed different various readings within normal range. P0171 was showing set as a permanent code.
I replaced the sensor with a Denso unit and reset the codes, and all seems well with the car (better, lower idle, etc.) -- but the voltage on O2 B1S1 still always shows 0.00V, even though the P0171 cleared. Also tried a different reader with the same result.
I didn't disconnect the battery to reset the ECM as of yet... but I wondered if there was something that was either keeping the system in closed loop, or causing it not to show the B1S1 voltage.
Any ideas, hypotheses or suggestions?
Thanks!
Any ideas?
Just replaced the upstream O2 sensor on our 2012 Forester (150k miles), due to the following codes:
- P0420 Catalyst System Efficiency Below Threshold
- P0171 System Too Lean
- P014D Manufacturer Defined - O2 Sensor Slow Response - Lean to Rich (Bank 1 Sensor 1)
- P014C Manufacturer Defined - O2 Sensor Slow Response - Rich to Lean (Bank 1 Sensor 1)
They were kicking on the Check Engine and Traction Control lights, and flashing the Cruise light. I also noticed that the O2 B1S1 voltage was reading 0.00 all the time. B1S2 showed different various readings within normal range. P0171 was showing set as a permanent code.
I replaced the sensor with a Denso unit and reset the codes, and all seems well with the car (better, lower idle, etc.) -- but the voltage on O2 B1S1 still always shows 0.00V, even though the P0171 cleared. Also tried a different reader with the same result.
I didn't disconnect the battery to reset the ECM as of yet... but I wondered if there was something that was either keeping the system in closed loop, or causing it not to show the B1S1 voltage.
Any ideas, hypotheses or suggestions?
Thanks!
Any ideas?