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I've never seen this before it is a 2013 chevy captiva with a 2.4 engine with the motor up to temp I turned the car off and just turned key back on to check some things on the scanner and noticed the 02 sensors volts keep rising here is a video showing it just let me know if anyone seen this ? my whole issue is car runs great till gets up to temp and it runs ruff and wants to stall it has 2 codes p0089 and p228D
Last edit: 3 years 1 day ago by bizz2222. Reason: To add video
In my opinion, this is probably due to the 450mv bias GM uses on oxygen sensor signal circuits.
If you watch from cold start, first key on, the oxygen sensors will report 450mv on the scan tool.
As the sensors warm up and begin creating voltage, the oxygen sensor signal will overcome the bias voltage and it will no longer be a factor. How quickly this voltage is overcome is a good indicator of o2 sensor heater operation and signal circuit integrity.
You are likely seeing the o2s cooling off and the bias voltage returning.
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