P0151 — O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
Category: Powertrain Severity: Medium
Updated:
DTC code P0151 means: O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1). It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty bank 2 upstream O2 sensor, bank 2 exhaust leak and vacuum leak; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty bank 2 upstream O2 sensor
- Bank 2 exhaust leak
- Vacuum leak
- Signal wire shorted to ground
Symptoms
- Check engine light
- Higher fuel consumption
- Rough idle
How to diagnose it step by step
- Identify bank 2.
- Check for exhaust leaks.
- Watch the sensor signal.
- Replace the sensor if it doesn't respond.
How to fix it
Same diagnosis as P0131 applied to bank 2 (the side of the engine without cylinder 1).
Estimated repair cost
$100–300.
Frequently asked questions
What does DTC code P0151 mean?
O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1).
Is code P0151 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0151?
Yes, you can drive; repair it soon.
Related codes
P0150 P0153 P0155 P0156 P0157 P0141 P0161 P0140 P0139 P0138
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