Check Engine Code
P0151
O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1)
Severity: medium
DIY difficulty: 2/5
Typical cost: $30–$300
What P0151 means
Bank 2 twin of P0131. Upstream sensor signal stuck below expected switching range.
Symptoms
- CEL
- Rough running
- Reduced economy
Likely causes (most common first)
- Exhaust leak upstream of the sensor
- Vacuum leak
- Failed O2 sensor
- Wiring short to ground
Can I keep driving?
Medium — drivable but fix soon
Typical repair cost
DIY fixes can start near $30 (parts only). Shop repairs for P0151 typically run up to $300 depending on the underlying cause and vehicle. Start with the most common cause — Exhaust leak upstream of the sensor — before throwing parts at it.
Recommended parts & tools for P0151
Most common fix for P0151:
Oxygen (O2) sensorOur buyer’s guides cover the tools and parts that pair with AXLY:
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