P1038 code

2012 TOYOTA RAV4
89,000 MILES • 2.5L • 4 CYL • 4WD • AUTOMATIC
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FIRASALAWY
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Hello,
my vehicle has the check engine light ,the track off, and 4WD on, on my dashboard for two years , the went off for a or a couple of of months then on again, i went to a couple of mechanics and the P1038 bank 1 sensor 2 code comes up every time, so I started by changing the oxygen sensor twice (purchase from Toyota dealer), then i changed the engine computer on left side, then checked all the wiring from computer to O2 sensor, and clear up the code and after forty minutes they lights are on again every time, please i need an expert help. lots of thanks .
Apr 8, 2017 at 8:20 PM
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CARADIODOC
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I cannot find any listing for that fault code in any of my sources. What is the exact definition you found for that code? The closest I came is it refers to a nitrogen oxides sensor open circuit for a few models.
Apr 8, 2017 at 8:42 PM
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FIRASALAWY
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sorry I mean the code P0138 oxygen sensor (bank 1 sensor 2).
Apr 9, 2017 at 8:55 AM
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CARADIODOC
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P0138 - Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)

I like that better. This code usually is not caused by the sensor. "Voltage too high" codes most commonly are caused by a cut wire or a corroded connector terminal. The Engine Computer puts a voltage on the signal line, but it is overcome by the sensor's voltage. When there's a break in the circuit, the sensor's voltage can't get back to the computer, but that little test voltage put out by the computer is what it sees.

You can verify this by observing the signal voltage on a scanner.
Apr 10, 2017 at 12:31 PM