P0157
Low SeverityO2 Sensor Circuit Low Voltage (Bank 2, Sensor 2)
Emissions System
What Does P0157 Mean?
Downstream O2 sensor bank 2 reads low voltage.
Common Fix
Replace downstream O2 sensor
Estimated Cost (DIY)
$25 - $80
Common Causes
How to Diagnose P0157
- 1Monitor sensor voltage
- 2Check for exhaust leaks
- 3Replace sensor
OEM Diagnostic Flowchart
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Read live data and freeze frame for P0157 to pinpoint the cause before buying parts.
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0157.
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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Open the exact repair flow most commonly associated with P0157 on this vehicle.
Open the exact repair flow most commonly associated with P0157 on this vehicle.
Related Codes
General fault in the downstream O2 sensor on bank 2.
Downstream O2 sensor bank 2 reads high (rich).
Downstream O2 sensor on bank 1 is reading too low. Could indicate a failing sensor or a lean exhaust condition.
Frequently Asked Questions
- Is P0157 just like P0137?
- Yes — same problem, other bank. P0137 is bank 1, P0157 is bank 2.
- Do I need to fix this?
- Only needed for emissions testing. No driveability impact.
Related Repair Guides
If your vehicle has triggered P0157, these DIY repair guides may help: