P0151
Medium SeverityO2 Sensor Circuit Low Voltage (Bank 2, Sensor 1)
Emissions System
What Does P0151 Mean?
Upstream O2 sensor on bank 2 is stuck low, reading lean.
Common Fix
Replace O2 sensor
Estimated Cost (DIY)
$30 - $100
Common Causes
How to Diagnose P0151
- 1Check for vacuum leaks on bank 2 side
- 2Monitor sensor voltage
- 3Check fuel trim for bank 2
- 4Replace sensor if stuck
OEM Diagnostic Flowchart
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0151.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL Denali AWD V8-6.2L Service Manual | Operation CHARM Operation CHARM : Car...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL Denali 2WD V8-6.2L Service Manual | Operation CHARM Operation CHARM : Car...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 4WD V8-6.0L Service Manual | Operation CHARM Operation CHARM : Car repair...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 4WD V8-5.3L Service Manual | Operation CHARM Operation CHARM : Car repair...
Related Symptoms
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Exact Repair Workflows
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Related Codes
General fault with the upstream O2 sensor on bank 2 of a V-engine.
Same as P0171 but on bank 2. If both P0171 and P0174 are present, the issue is likely shared (MAF, fuel pump, or large vacuum leak).
Upstream O2 sensor bank 2 reads too high (rich).
Frequently Asked Questions
- Why only bank 2?
- If only bank 2 is lean, the issue is likely specific to that side — a vacuum leak, exhaust leak, or bad sensor on that bank.
- Can I swap bank 1 and bank 2 sensors to test?
- Yes — if the code follows the sensor, the sensor is bad. If it stays on bank 2, the problem is something else.
Related Repair Guides
If your vehicle has triggered P0151, these DIY repair guides may help: