P0138 on Chevrolet Malibu
O2 Sensor Circuit High Voltage Bank 1 Sensor 2
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Chevrolet Malibu context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for P0138.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What P0138 Means on Your Chevrolet Malibu
P0138 is a diagnostic trouble code indicating: O2 Sensor Circuit High Voltage Bank 1 Sensor 2. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Chevrolet Malibu Owner Reports
Source: NHTSA Complaints Database
"The contact owns a 2017 Chevrolet Malibu. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The mechanic retrieved fault code: P0138 (engine control module (ECM)."
"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 in acceleration after pressing the gas pedal, putting driver"
"I purchased a 2017 chevy malibu in april 2017 with 11 miles. in less than a month, the car started having issues."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Chevrolet Malibu
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.