P0158 Subaru Code - HO2S22 Circuit High Voltage
Quick Answer
The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0158 Subaru indicates HO2S22 Circuit High Voltage.
- Common causes
- Common causes include Faulty Rear Heated Oxygen Sensor Bank 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0158 Subaru Description
What are the Possible Causes of the DTC P0158 Subaru?
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks
- Exhaust gas leaks
How to Fix the DTC P0158 Subaru?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0158 Subaru code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0158 Subaru Code
What does the OBDII code P0158 mean for a Subaru?
P0158 indicates that the voltage in the downstream oxygen sensor (HO2S22) of Bank 2 is higher than the expected range, suggesting a possible issue with the sensor or related components.
What are the common symptoms of code P0158 in a Subaru?
Symptoms may include poor fuel efficiency, rough idle, reduced engine performance, and the check engine light being illuminated.
What causes the P0158 code in a Subaru?
Common causes include a faulty oxygen sensor, shorted wiring or connections, exhaust leaks, or issues with the engine control module (ECM).
Can a faulty oxygen sensor trigger the P0158 code?
Yes, a failing downstream oxygen sensor (Bank 2, Sensor 2) is a primary cause of this code.
How do I diagnose the P0158 code on a Subaru?
Start by inspecting the oxygen sensor, wiring, and connectors for damage or corrosion, then use a multimeter to test the voltage readings.
Is it safe to drive with the P0158 code on my Subaru?
While it may be safe for short distances, prolonged driving can lead to poor engine performance and potential damage to other components.
How can I fix the P0158 code on a Subaru?
Repairs may include replacing the faulty oxygen sensor, repairing damaged wiring, or addressing exhaust system leaks.
Can an exhaust leak cause the P0158 code?
Yes, an exhaust leak near the oxygen sensor can create inaccurate readings and trigger the code.
Do I need to replace the ECU if I get the P0158 code?
Replacing the ECU is rare; most P0158 cases are resolved by fixing sensor or wiring issues.
How much does it cost to repair the P0158 code on a Subaru?
Costs can vary but typically range from $100 to $300 for sensor replacement, depending on labor rates and parts prices.
Discuss the causes and fixes for P0158 Subaru OBDII Code
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