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P0139 2009 Honda Accord Code - HO2S Bank 1 Sensor 2 Slow Response

Quick Answer

The P0139 diagnostic trouble code (DTC) for a 2009 Honda Accord refers to a potential issue with the oxygen sensor located downstream of the catalytic converter on bank 1 of the engine. Common causes include Faulty oxygen sensor, Wiring or connector issues, Exhaust leaks. 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
P0139 2009 Honda Accord indicates HO2S Bank 1 Sensor 2 Slow Response.
Common causes
Common causes include Faulty oxygen sensor, Wiring or connector issues, Exhaust leaks.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 11, 2024
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Code P0139 2009 Honda Accord Description

The P0139 diagnostic trouble code (DTC) for a 2009 Honda Accord refers to a potential issue with the oxygen sensor located downstream of the catalytic converter on bank 1 of the engine. This sensor, known as the HO2S (Heated Oxygen 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. A "slow response" from this sensor indicates that it is not functioning as quickly or accurately as it should, which can lead to various performance issues in the vehicle.

OBDII Code P0139 2009 Honda Accord - HO2S Bank 1 Sensor 2 Slow Response
P0139 2009 Honda Accord Code - HO2S Bank 1 Sensor 2 Slow Response

Common Causes of P0139 2009 Honda Accord

  1. Faulty oxygen sensor
  2. Wiring or connector issues
  3. Exhaust leaks
  4. Contaminated sensor
  5. Catalytic converter malfunction

Symptoms of P0139 2009 Honda Accord

  1. Decreased fuel efficiency
  2. Rough idling or stalling
  3. Engine misfires
  4. Reduced acceleration
  5. Increased emissions

How to Fix P0139 2009 Honda Accord

  1. Use an OBD-II scanner to read and record the specific trouble code.
  2. Inspect the wiring and connectors for any damage or corrosion.
  3. Test the oxygen sensor using a multimeter to determine if it is functioning within specifications.
  4. Replace the oxygen sensor if it is found to be faulty or not responding correctly.
  5. Clear the trouble code and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P0139 2009 Honda Accord

The cost of repairing a HO2S Bank 1 Sensor 2 slow response code can vary depending on the specific cause of the issue and the labor rates at the repair shop. On average, the replacement oxygen sensor can cost between $50 to $200, while labor costs can range from $100 to $200. Overall, the total repair cost for this issue could typically be between $150 to $400. It's recommended to consult with a professional mechanic for a more accurate estimate based on your location and vehicle details.

What does this mean?

Tech Notes for P0139 2009 Honda Accord

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

When is the Code Detected?

The P0139 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor takes more time to respond between rich and lean than the specified time.

Need more information about the P0139 2009 Honda Accord code?

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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 P0139 2009 Honda Accord Code

1. What are the common symptoms of OBDII code P0139 on a 2009 Honda Accord?

- Common symptoms include poor fuel efficiency, rough idling, engine hesitation, and the illumination of the check engine light.

2. What does the HO2S Bank 1 Sensor 2 Slow Response code indicate in a 2009 Honda Accord?

- This code indicates that the oxygen sensor downstream of the catalytic converter in bank 1 is not responding quickly enough to changes in the air-fuel mixture.

3. What are the possible causes of the HO2S Bank 1 Sensor 2 Slow Response code on a 2009 Honda Accord?

- Possible causes include a faulty oxygen sensor, wiring issues, exhaust leaks, engine misfires, or a malfunctioning catalytic converter.

4. How can I diagnose the HO2S Bank 1 Sensor 2 Slow Response code on my 2009 Honda Accord?

- Diagnosis typically involves using an OBDII scanner to read the code, checking the oxygen sensor's wiring and connections, and performing tests to identify the root cause of the slow sensor response.

5. Is it safe to continue driving my 2009 Honda Accord with the P0139 code present?

- It is recommended to address the issue promptly to prevent potential damage to the catalytic converter and ensure optimal engine performance.

6. Can I reset the check engine light after fixing the HO2S Bank 1 Sensor 2 Slow Response issue on my 2009 Honda Accord?

- Yes, once the underlying problem is fixed, the check engine light can be reset using an OBDII scanner or by disconnecting the car's battery for a few minutes.

7. How much does it typically cost to repair the HO2S Bank 1 Sensor 2 Slow Response problem on a 2009 Honda Accord?

- The cost of repair can vary depending on the cause of the issue, but it may involve replacing the oxygen sensor, repairing wiring, or addressing other related components. Costs can range from $100 to $400 or more.

8. Can I fix the HO2S Bank 1 Sensor 2 Slow Response issue on my 2009 Honda Accord myself?

- DIY repair is possible for some individuals, especially if experienced with automotive maintenance. However, it's recommended to consult a professional if unsure about diagnosing or fixing the problem.

9. How often does the HO2S Bank 1 Sensor 2 Slow Response code occur in a 2009 Honda Accord?

- While the frequency can vary, this code may occur intermittently or as a one-time occurrence, depending on the specific issue causing the slow sensor response.

10. Will the HO2S Bank 1 Sensor 2 Slow Response issue affect the overall performance of my 2009 Honda Accord?

- Yes, unresolved issues related to this code can lead to decreased fuel efficiency, engine performance issues, and potential damage to the catalytic converter over time.

Discuss the causes and fixes for P0139 2009 Honda Accord OBDII Code

Submit a New Comment

  • Check engine came on, I ran the code reader and resulted with P0139 HONDA - HO2S Bank 1 Sensor 2 Slow Response. I am replacing it ASAP.

    Can anyone give me a detail location for it (photos/diagrams)?

    Thank you

    Reply to Comment

  • Do you have 4 or 6 Cyl? Here are the only images I got.

    Location for the 6 Cylinder engine. Bank 1 Sensor 2 (Rear)

    1. Raise the vehicle on a lift.
    2. Disconnect the rear secondary HO2S 4P connector (A), and remove the harness clamps (B).
    Location of Rear Secondary HO2S 4P Connector And Harness Clamps With Torque Specifications
    3. Remove rear secondary HO2S (C).
    4. Install the parts in the reverse order of removal.

    Image

    Click here to enlarge image

    Location for the 4 Cylinder engine

    Image

    Click here to enlarge image

    Reply to Comment

  • Hi, is a 4 cylinder.

    Reply to Comment

  • Thank you. I replace it. Now I have to run the car until the evap cycle completes.

    Reply to Comment