AutoCodes – Honda – P0139 1997 Honda Civic

P0139 1997 Honda Civic Code - HO2S Bank 1 Sensor 2 Slow Response

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 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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: P0139 1997 Honda Civic indicates HO2S Bank 1 Sensor 2 Slow Response.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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 4,702

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 Mar 31, 2024

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 1997 Honda Civic 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 P0139 1997 Honda Civic - HO2S Bank 1 Sensor 2 Slow Response - AutoCodes.com — P0139 1997 Honda Civic Code - HO2S Bank 1 Sensor 2 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 1997 Honda Civic?

Faulty Rear Heated Oxygen Sensor Bank 1
Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0139 1997 Honda Civic?

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 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0139 1997 Honda Civic 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 P0139 1997 Honda Civic 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 1997 Honda Civic Code

1. What are the common symptoms of OBDII code P0139 on a 1997 Honda Civic?

- Common symptoms include poor fuel economy, rough idling, and potential stalling of the vehicle.

2. What does the HO2S Bank 1 Sensor 2 Slow Response code indicate in a 1997 Honda Civic?

- This code indicates that the oxygen sensor in Bank 1, Sensor 2 is not responding quickly enough to changes in the air-fuel mixture.

3. What are the typical causes of a slow response from the HO2S Bank 1 Sensor 2 in a 1997 Honda Civic?

- Possible causes include a faulty oxygen sensor, wiring issues, exhaust leaks, or a problem with the engine's air-fuel mixture.

4. How can I diagnose the cause of OBDII code P0139 on my 1997 Honda Civic?

- You can use a scan tool to monitor the oxygen sensor's response time, check for any exhaust leaks, inspect the sensor wiring, and test the sensor's voltage output.

5. Can I continue driving my 1997 Honda Civic with the HO2S Bank 1 Sensor 2 Slow Response code?

- It is not recommended to drive for an extended period with this code active, as it can lead to decreased fuel efficiency and potential damage to the catalytic converter.

6. How can I repair OBDII code P0139 on a 1997 Honda Civic?

- Repair options include replacing the oxygen sensor, repairing any wiring issues, fixing exhaust leaks, and ensuring the air-fuel mixture is within the correct range.

7. Will resetting the OBDII code P0139 on my 1997 Honda Civic make it go away permanently?

- Resetting the code may temporarily turn off the check engine light, but if the underlying issue is not addressed, the code is likely to return.

8. Can a dirty air filter cause the HO2S Bank 1 Sensor 2 Slow Response code on a 1997 Honda Civic?

- While a dirty air filter can impact engine performance, it is not a common cause of this specific OBDII trouble code.

9. How much does it typically cost to repair OBDII code P0139 on a 1997 Honda Civic?

- The cost can vary depending on the cause of the issue, but replacing the oxygen sensor alone can range from $100 to $300, including parts and labor.

10. Is it possible to prevent OBDII code P0139 from appearing on my 1997 Honda Civic?

- Regular maintenance of the vehicle, including timely replacement of oxygen sensors and addressing any engine performance issues promptly, can help prevent this code from appearing.