P0138 Downstream bank 1 oxygen sensor reading stuck high
4 owner reports and 79 manufacturer filings across 42 model years from Chevrolet, Ford, GMC, Infiniti and others.
Where P0138 shows up
Source: NHTSA manufacturer communications and complaintsShowing the 25 model years where P0138 appears most; it is on file for 42 in total.
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
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P0138 by make
The same record, one make at a time: the model years, bulletins and owner reports that name P0138 on that maker’s vehicles.
What it gets filed under
What owners said
Source: NHTSA complaint databaseOwners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.
OBD2 codes ran on vehicle show: P0138 ("O2 sensor circuit High voltage bank 1 sensor 2") P013E (unknown) P2138 ("Throttle/Pedal Position Sensor Switch D/E Voltage Correlation") Vehicle is getting poor fuel mileage and has a drastic delay…
79 manufacturer filings name P0138. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P0138.
- 09-115-24R Service bulletin2025-04-22 · Electrical System
- "This bulletin announces the availability of new oxygen sensors developed to address the following Diagnostic Trouble Codes (DTCs) detected by the Engine Control Module: • P0137: O2 Sensor Circuit Low Voltage Bank 1 Sensor 2 • P0138: O2 Sensor Circuit High Voltage Bank 1 Sensor 2 • P0140: O2 Sensor Circuit No Activity Detected Bank 1 Sensor 2 • P0141: O2 Sensor Heater Circuit Bank 1 Sensor 2"
- 09-115-24 Service bulletin2024-05-14 · Electrical System
- This bulletin announces the availability of new oxygen sensors developed to address the following Diagnostic Trouble Codes (DTCs); P0137 (O2 Sensor Circuit Low Voltage Bank 1 Sensor 2, P0138 (O2 Sensor Circuit High Voltage Bank 1 Sensor 2) P0140 (O2 Sensor Circuit No Activity Detected Bank 1 Sensor 2), and P0141 (O2 Sensor Heater Circuit Bank 1 Sensor 2).
- SSM 51048 Service bulletin2022-08-23 · Electrical System
- Some 2021-2022 Bronco Sport vehicles equipped with 2.0L engine may exhibit a malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0036 and/or P0138 stored in the powertrain control module (PCM). This may be due to corrosion or water intrusion in connector C201 and/or C1570. Prior to performing Workshop Manual (WSM) diagnostics, inspect the male and female side of connector C201 a
- SSM 50993 Service bulletin2022-08-03 · Electrical System
- Some 2022 Maverick vehicles built on or before 4-Apr-2022 equipped with 2.0L engine may exhibit a charging system warning indicator with diagnostic trouble codes (DTCs) U012D, U0284 and/or U042E stored in the powertrain control module (PCM). The vehicle may also exhibit a malfunction indicator lamp (MIL) with DTCs P0036:00 and/or P0138:00 stored in the PCM. This may be caused by water intrusion in
- SSM 50973 Service bulletin2022-07-29 · Electrical System
- Some 2022 Maverick vehicles built on or before 4-Apr-2022 equipped with 2.0L engine may exhibit a charging system warning indicator with diagnostic trouble codes (DTCs) U012D, U0284 and/or U042E stored in the powertrain control module (PCM). The vehicle may also exhibit a malfunction indicator lamp (MIL) with DTCs P0036:00 and/or P0138:00 stored in the PCM. This may be caused by water intrusion in
- 19NA077 Service bulletin2019-11-22 · Electrical System
- This technical bulletin provides repair information to correct a customer concern of Start/Stop Performance, Hesitation From a Stop, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0132 and/or P0138 Set.
What P0138 means
Source: SAE J2012 / OBD-IIDownstream bank 1 oxygen sensor reading stuck high.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about P0138
Source: NHTSA files and the OBD-II standardCan I keep driving with P0138 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.