The Lemon IndexThe downstream O2 sensor reads too high.
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
Failed O2 sensor. Then: wiring fault; engine running rich.
Owners named P0138 in 10 complaints to the U.S. government, most often on the Chevrolet Malibu.
Cars owners report it on
Complaints that name P0138, by model. Raw counts, not a failure rate: popular models get more complaints.
Years owners report it on most: 2017 Chevrolet Malibu
The details
What P0138 means
The downstream O2 sensor reads too high.
Can I drive with P0138?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
Common causes of P0138
- Failed O2 sensor
- Wiring fault
- Engine running rich
A shop should confirm the cause with a scan and tests before replacing parts.
Model years that report P0138 most
Related codes
P0137 P0136 P0135 P0133 P0131 P0140 P0141 P0128
Quick answers
What does P0138 mean?
O2 Sensor Circuit High Voltage (Bank 1 Sensor 2). The downstream O2 sensor reads too high.
Can I drive with P0138?
Drive on, get it checked. You can usually keep driving. Have the code read at your next service or within a few weeks.
What causes P0138?
Failed O2 sensor; Wiring fault; Engine running rich.
Counts: NHTSA owner complaints whose text names P0138. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.