Replaced Downstream O2 Sensor

[06YarisRS]

I've had a check engine light on since I bought the car. According to Torque Pro OBD2, I had zero volts on the bank 1 sensor 2. So, I replaced the sensor today and was disappointed that it still read 0 volts while idling in my driveway, however the MIL did not return. But I went for a drive and now it works. Getting a good sweep from 0.1 to 0.9 volts and air fuel ratios, commanded and measured, are perfectly in sync. I found the answer on another Toyota model car/truck forum.

Anyone want to guess why it didn't appear to work at first? :biggrin:

[SirDigby]

maybe when it was in open loop it had not sent voltage to sensor yet. (?)

[06YarisRS]

maybe when it was in open loop it had not sent voltage to sensor yet. (?)

It may be. But, I don't really understand the concept of open loop even after reading a couple of explanations. My pea brain was incapable of grasping the idea. :biggrin: But, it sounds like you are on the right track in that it did not show a voltage until a certain condition was met. What condition do you think that was? It is different than my Kia's sensors as they will start to show fluctuating voltages from the 02 sensors as soon as it's started.

I don't know much about vehicle electronics.

Wish me luck as I paid $18.00 USD on eBay for this sensor. It's a cheap knockoff, but seems to work - so far anyway.

[Bluevitz-rs]

The sensor needs to heat up before it works. O2 sensors create their own voltage, so what you're reading isn't anything sent from the computer. It only reads what the sensor sends it.

[06YarisRS]

The sensor needs to heat up before it works. O2 sensors create their own voltage, so what you're reading isn't anything sent from the computer. It only reads what the sensor sends it.

:thumbup: Yes! I read that it has to reach, I believe, 600F before it sends voltage. Thanks for playing, both of you! :smile:

[Neinris]

I have multiple faults and I think it’s my downstream O2 sensor that’s most likely the culprit. I went underneath the car, but the connection leads inside the cabin. Where is it exactly located? :confused:

[Neinris]

Just want to share the youtube video you sent me:

https://www.youtube.com/watch?v=yT5Wgs1b6wg

[06YarisRS]

Just want to share the youtube video you sent me:

https://www.youtube.com/watch?v=yT5Wgs1b6wg

Glad it helped you!

[remcafee]

start saving for an oem sensor, i replace tons of aftermarket sensors on customer cars coming to the dealer complaining another shop fixed their car a month ago and it has the same error codes back on again