P0138 on Subaru vehicles Downstream bank 1 oxygen sensor reading stuck high
P0138 is named on 33 Subaru model years (2017–2024): 66 manufacturer filings and 0 owner reports in NHTSA’s files, across BRZ, Crosstrek, Forester, Impreza, Legacy and 1 more.
Which Subaru model years name P0138
Source: NHTSA manufacturer communications and complaintsA model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.
Subaru filings that name P0138
Source: NHTSA manufacturer communicationsBulletins and campaigns Subaru filed with NHTSA whose summary names P0138. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- 09-115-24 Service bulletin2024-05-14 · Engine
- 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).
- 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"
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. The record above is what Subaru and its owners have filed about it; the code’s page across every make has the whole file.
Common questions
Source: NHTSA files and the OBD-II standardIs P0138 a known problem on Subaru vehicles?
It is a documented one: NHTSA's files hold 66 manufacturer filings and 0 owner reports naming P0138 on 33 Subaru model years (2017–2024). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Subaru models does P0138 appear on most?
2023 BRZ (2 documents), 2022 BRZ (2 documents), 2024 Crosstrek (2 documents).
Does P0138 on a Subaru mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.