![]() 03/15/2020 at 12:06 • Filed to: Aristo, Toyota Aristo, Lexus GS | ![]() | ![]() |
When I bought the GS back in December, the CEL was on for code P0156, the rear O2 sensor. It’s not THAT difficult of a fix, but it requires peeling back part of the passenger’s side footwell carpet because the plug is under the center console. Changed it out yesterday, took it out for a test drive, CEL came back on. Same code. What else would cause that? Exhaust leak, maybe?
![]() 03/15/2020 at 12:28 |
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that code means “ O2 Sensor Circuit Malfunction Bank 2 Sensor 2.” which means the problem could be anywhere in the wiring between the PCM and the sensor.
![]() 03/15/2020 at 12:33 |
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One forum I read says the connector itself -- you know the ckicky thingie that connects to the new O2 sensor thingie -- was damaged/old enough that it won't recognize a new sensor. There should (hopefully) be a part number visible on the thing.
![]() 03/15/2020 at 12:37 |
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As the others said, check the connector. I’d troubleshoot in this order: wiring, exhaust leak, faulty new sensor.
![]() 03/15/2020 at 13:00 |
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Two things - if you didn’t erase codes, will take several startup cycles to clear. The other thing that might help is cleaning the connector with contact cleaner and using some dielectric grease.
![]() 03/15/2020 at 13:03 |
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I unplugged the battery, and it came on after about 45 minutes of driving. I’ll try the connector.
![]() 03/15/2020 at 13:05 |
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If you have an obd reader to look at live data see if the sensor fluctuates between 0 .1v and 1v, if it does I'd start looking at exhaust problems. The fluctuations would indicate the wiring is intact.
![]() 03/15/2020 at 13:09 |
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Mine only reads and erases codes, but I’ll ask around.
![]() 03/16/2020 at 18:22 |
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It’s an exhaust leak. Confirmed today.
![]() 03/16/2020 at 18:23 |
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Confirmed it’s an exhaust leak today.
![]() 03/16/2020 at 18:49 |
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well, at least its the most straightforward fix, hopefully.
![]() 03/16/2020 at 19:44 |
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Could be worse!