P0158
Low SeverityO2 Sensor Circuit High Voltage (Bank 2, Sensor 2)
Emissions System
What Does P0158 Mean?
Downstream O2 sensor bank 2 reads high (rich).
Common Fix
Replace downstream O2 sensor
Estimated Cost (DIY)
$25 - $80
Symptoms
- ⚠️Check engine light
- ⚠️Failed emissions
Common Causes
Failed sensor stuck richlikely
Rich condition from upstream issuepossible
How to Diagnose P0158
- 1Check upstream bank 2 for rich condition first
- 2Monitor sensor voltage
- 3Replace sensor
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Frequently Asked Questions
- Can this be caused by a bank 2 issue?
- If bank 2 upstream is running rich, the downstream sensor correctly reads high. Fix any upstream codes first.
- Is the downstream sensor expensive?
- No — downstream sensors are often cheaper than upstream. $25-$80 for DIY.