AutoCodes – Saturn – P0158 Saturn

P0158 Saturn Code - HO2S Circuit High Voltage Bank 2 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. 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 Saturn indicates HO2S Circuit High Voltage Bank 2 Sensor 2.
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.

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Code Popularity 4,400

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 27, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0158 Saturn Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the HO2S voltage is greater than 1, 050 mV.

OBDII Code P0158 Saturn - HO2S Circuit High Voltage Bank 2 Sensor 2 - AutoCodes.com — P0158 Saturn Code - HO2S Circuit High Voltage Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0158 Saturn?

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
Low or high fuel system pressure
Fuel contamination
Faulty fuel injectors
Exhaust gas leaks
Engine vacuum leaks

How to Fix the DTC P0158 Saturn?

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.

What does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor Bank 2 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0158 Saturn 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.

Need more information about the P0158 Saturn code?

Need more information on how to fix the P0158 Saturn code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0158 Saturn code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0158 Saturn Code

1. What are common symptoms of OBDII code P0158 on a Saturn?

The common symptoms of code P0158 include poor fuel economy, rough idling, engine misfires, and the illumination of the Check Engine Light.

2. What does the HO2S Circuit High Voltage Bank 2 Sensor 2 code mean for a Saturn?

The P0158 code indicates that the oxygen sensor located on Bank 2 Sensor 2 in the exhaust system is detecting a high voltage condition.

3. What are the possible causes of OBDII code P0158 on a Saturn?

Possible causes of code P0158 include a faulty oxygen sensor, wiring issues, exhaust leaks, engine misfires, or issues with the vehicle's fuel system.

4. How can I diagnose the HO2S Circuit High Voltage Bank 2 Sensor 2 code on my Saturn?

Diagnosing code P0158 typically involves using an OBDII scanner to read the code, inspecting the oxygen sensor and its wiring, checking for exhaust leaks, and testing the vehicle's fuel system components.

5. Can I drive my Saturn with OBDII code P0158?

It is not recommended to continue driving your Saturn with code P0158, as it can lead to further engine damage and reduced fuel efficiency. It's best to address the issue promptly.

6. How do I repair OBDII code P0158 on my Saturn?

Repairing code P0158 may involve replacing the oxygen sensor on Bank 2 Sensor 2, repairing any damaged wiring, fixing exhaust leaks, addressing engine misfires, or repairing issues with the fuel system.

7. Is OBDII code P0158 an expensive repair on a Saturn?

The cost of repairing code P0158 on a Saturn can vary depending on the exact cause of the issue. It's recommended to have a professional diagnose the problem to get an accurate estimate.

8. Can a DIY enthusiast fix OBDII code P0158 on a Saturn?

While some aspects of diagnosing and repairing code P0158 can be done by a DIY enthusiast, it's recommended to seek professional help, especially when dealing with complex issues like oxygen sensor replacement or wiring repairs.

9. How urgent is it to address OBDII code P0158 on a Saturn?

It's important to address code P0158 promptly to prevent potential engine damage and ensure optimal fuel efficiency. Ignoring the issue can lead to more severe problems in the long run.

10. Will resetting the Check Engine Light resolve OBDII code P0158 on a Saturn?

Simply resetting the Check Engine Light without addressing the underlying issue causing code P0158 will not solve the problem. It's crucial to diagnose and repair the root cause of the code to prevent it from reoccurring.