Code result
P0151
O2 Sensor Circuit Low Voltage
Moderate severity
What it means
Same condition as P0131 but on bank 2. The upstream sensor sees a continuously lean exhaust on bank 2 or has a signal short to ground.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Exhaust leak upstream of the sensor
highOne of the most commonly reported causes for this code — check this first.
Bank 2 running lean (vacuum leak, fuel pressure)
mediumA plausible cause — test and verify before replacing parts.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Related help
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P0151 freeNo credit card required