Engine-CodesScion – P0157 Scion

P0157 Scion Code - HO2S22 Circuit Low Voltage

Quick Answer

The P0157 Scion code indicates a problem with the HO2S22 (Heated Oxygen Sensor 2 Bank 2) circuit, specifically a low voltage condition. Common causes include Faulty HO2S22 sensor, Damaged wiring or connectors in the sensor circuit, Exhaust leaks near the sensor. 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
P0157 Scion indicates HO2S22 Circuit Low Voltage.
Common causes
Common causes include Faulty HO2S22 sensor, Damaged wiring or connectors in the sensor circuit, Exhaust leaks near the sensor.
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.
Table of contents Created and updated by William Orellana on Sep 12, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0157 Scion Description

The P0157 Scion code indicates a problem with the HO2S22 (Heated Oxygen Sensor 2 Bank 2) circuit, specifically a low voltage condition. The HO2S22 sensor is responsible for monitoring the oxygen levels in the exhaust gases and providing feedback to the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion. When the voltage from the sensor is lower than expected, it can lead to issues with fuel efficiency, emissions, and overall engine performance.

OBDII Code P0157 Scion - HO2S22 Circuit Low Voltage
P0157 Scion Code - HO2S22 Circuit Low Voltage

Common Causes of P0157 Scion

  1. Faulty HO2S22 sensor
  2. Damaged wiring or connectors in the sensor circuit
  3. Exhaust leaks near the sensor
  4. ECM software issue
  5. Engine running rich or lean

Symptoms of P0157 Scion

  1. Decreased fuel efficiency
  2. Rough idling or stalling
  3. Engine hesitation or surging
  4. Check Engine Light illuminated
  5. Failed emissions test

How to Fix P0157 Scion

  1. Use a scan tool to verify the P0157 code and monitor live data from the oxygen sensor.
  2. Inspect the wiring and connectors for any damage or corrosion, repairing or replacing as needed.
  3. Test the HO2S22 sensor using a multimeter to check for proper voltage output.
  4. Replace the HO2S22 sensor if it is found to be faulty.
  5. Clear the code and perform a test drive to ensure the issue has been resolved.

Cost to Fix P0157 Scion

The typical repair costs for addressing a P0157 Scion code can range from $150 to $300, including parts and labor. However, the specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. It's advisable to check local rates for a more precise estimate. Keep in mind that rates in metropolitan areas or at dealerships may be higher, while independent shops often charge less.

Tech Notes for P0157 Scion

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

When is the Code Detected?

The P0157 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor signal voltage remains excessively low for an extended period of time.

Need more information about the P0157 Scion code?

Need more information on how to fix the P0157 Scion code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0157 Scion 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 P0157 Scion Code

No Frequently Asked Questions about P0157 Scion Code found.

Discuss the causes and fixes for P0157 Scion OBDII Code

Code P0157 Scion comments

No comments found for this page.