P0131 on Chevrolet
O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
P0131 on Chevrolet vehicles indicates o2 sensor circuit low voltage (bank 1, sensor 1). Au7o has documented this code across 1 Chevrolet model — most commonly on Sonic. This code means the upstream oxygen (O2) sensor on Bank 1, Sensor 1 — located before the catalytic converter — is reporting an abnormally low voltage, which the computer reads as a persistently lean exhaust (too much oxygen). The computer uses this sensor to fine-tune the air-fuel mixture, and a stuck-low signal disrupts that feedback. The low reading can come from an actual lean condition in the engine or from a faulty sensor or its wiring. Symptoms may include rough running, hesitation, and reduced fuel economy. Typical repair costs on Chevrolet range from $50 to $500, depending on the specific model and root cause.
Common Causes of P0131
- •Vacuum or intake air leak (true lean condition)
- •Failed or contaminated upstream O2 sensor
- •Exhaust leak ahead of the sensor
- •Low fuel pressure or weak/clogged fuel injectors
- •Corroded or loose O2 sensor connector
- •Damaged or shorted-to-ground sensor wiring
- •Dirty mass airflow sensor skewing fuel trims
- •Faulty PCM/ECM (rare)
P0131 on Chevrolet by Model
Chevrolet Sonic(1 issue)
- Persistent Check Engine Light and Electrical System Faults2012-2016
Early Chevrolet Sonic models are prone to persistent check engine light illumination with various electrical system faults. The 2012 model year in particular has a reputation for the check engine light activating with no clear mechanical cause. Issues range from faulty oxygen sensors and MAP sensors to ECM communication errors. The vehicle has been recalled 7 times for the 2012 model year alone across electrical and safety systems.
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What does P0131 mean on Chevrolet?▼
P0131 stands for "O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)." This code means the upstream oxygen (O2) sensor on Bank 1, Sensor 1 — located before the catalytic converter — is reporting an abnormally low voltage, which the computer reads as a persistently lean exhaust (too much oxygen). The computer uses this sensor to fine-tune the air-fuel mixture, and a stuck-low signal disrupts that feedback. The low reading can come from an actual lean condition in the engine or from a faulty sensor or its wiring. Symptoms may include rough running, hesitation, and reduced fuel economy. On Chevrolet specifically, this code is documented across 1 model.
What causes P0131 on Chevrolet vehicles?▼
Common causes on Chevrolet: Vacuum or intake air leak (true lean condition), Failed or contaminated upstream O2 sensor, Exhaust leak ahead of the sensor, Low fuel pressure or weak/clogged fuel injectors, Corroded or loose O2 sensor connector. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0131 on a Chevrolet?▼
Repair costs on Chevrolet range from $50 to $500, depending on the specific model and root cause.
Which Chevrolet models have P0131 documented?▼
Au7o has documented P0131 on 1 Chevrolet model: Sonic.