AutoCodes – Acura – P0157 Acura

P0157 Acura Code - O2 Sensor Circuit Low Voltage Bank 2 Sensor 2

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: P0157 Acura indicates O2 Sensor Circuit Low 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 18,766

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 Sep 28, 2020

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0157 Acura Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0157 Acura - O2 Sensor Circuit Low Voltage Bank 2 Sensor 2 - AutoCodes.com — P0157 Acura Code - O2 Sensor Circuit Low Voltage Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0157 Acura?

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 may be faulty
Exhaust gas leaks

How to Fix the DTC P0157 Acura?

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.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0157 Acura 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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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 Acura Code

1. What are the common symptoms of OBDII code P0157 in an Acura vehicle?

- Common symptoms include poor fuel economy, rough idling, stalling, and an illuminated check engine light.

2. What does the OBDII code P0157 in an Acura indicate?

- The code P0157 indicates a low voltage condition in the O2 sensor circuit of Bank 2 Sensor 2 in the vehicle's exhaust system.

3. What are the possible causes of OBDII code P0157 in an Acura?

- Possible causes include a faulty O2 sensor, damaged wiring or connectors in the sensor circuit, exhaust leaks, or a malfunctioning engine control module (ECM).

4. How can I diagnose the O2 sensor circuit low voltage issue in Bank 2 Sensor 2 of my Acura?

- To diagnose the issue, you can use a scan tool to monitor the O2 sensor's voltage readings, visually inspect the sensor and its wiring, and perform a smoke test to check for exhaust leaks.

5. Can I drive my Acura with the OBDII code P0157 present?

- It is not recommended to drive your vehicle with the code P0157 present as it can lead to poor engine performance and potential damage if left unresolved.

6. How can I repair the O2 sensor circuit low voltage issue in Bank 2 Sensor 2 of my Acura?

- Repair options include replacing the faulty O2 sensor, repairing damaged wiring or connectors, fixing any exhaust leaks, and resetting the ECM to clear the code.

7. Is it possible for a contaminated O2 sensor to trigger the P0157 code in an Acura?

- Yes, a contaminated O2 sensor can cause incorrect voltage readings and trigger the P0157 code in Bank 2 Sensor 2 of an Acura vehicle.

8. Will cleaning the O2 sensor help resolve the low voltage issue in Bank 2 Sensor 2 of my Acura?

- Cleaning the O2 sensor may temporarily improve its performance, but if the code persists, it is recommended to replace the sensor for a long-term solution.

9. How long does it take to repair the O2 sensor circuit low voltage issue in an Acura?

- The repair time can vary depending on the exact cause of the issue, but it typically takes 1-2 hours to diagnose and repair the O2 sensor circuit problem.

10. Can a DIY enthusiast fix the OBDII code P0157 in an Acura at home?

- While some aspects of diagnosing and repairing the code can be done at home, it is recommended to seek professional help for accurate diagnosis and proper repair to ensure the issue is fully resolved.