AutoCodes – Honda – P0139 1998 Honda Civic

P0139 1998 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 1998 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 5,689

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 1998 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 1998 Honda Civic - HO2S Bank 1 Sensor 2 Slow Response - AutoCodes.com — P0139 1998 Honda Civic Code - HO2S Bank 1 Sensor 2 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 1998 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 1998 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 1998 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 1998 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 1998 Honda Civic Code

1. What are the common symptoms of OBDII code P0139 in a 1998 Honda Civic?

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

2. What does the OBDII code P0139 for a 1998 Honda Civic indicate?

- The code P0139 indicates a slow response from the heated oxygen sensor (HO2S) located in Bank 1, Sensor 2 of the exhaust system.

3. What are the possible causes of a slow response from the HO2S Bank 1 Sensor 2 in a 1998 Honda Civic?

- Potential causes include a faulty oxygen sensor, wiring issues, exhaust leaks, fuel pressure problems, or an engine misfire.

4. How can I diagnose the cause of OBDII code P0139 in my 1998 Honda Civic?

- Diagnose by checking the oxygen sensor's wiring for damage, inspecting for exhaust leaks, verifying proper fuel pressure, and scanning for other related trouble codes.

5. Can I drive my 1998 Honda Civic with OBDII code P0139?

- It is not recommended to drive extensively with code P0139 present, as it can lead to reduced fuel efficiency and potential damage to the catalytic converter.

6. How can I repair OBDII code P0139 in my 1998 Honda Civic?

- Repair options include replacing the HO2S Bank 1 Sensor 2, repairing any damaged wiring, fixing exhaust leaks, addressing fuel system issues, or resolving any engine misfires.

7. Is it safe to continue driving my 1998 Honda Civic if the check engine light is on due to code P0139?

- While the vehicle may still be operational, it is best to address the underlying issue promptly to prevent potential damage to the engine and emissions system.

8. How much does it cost to repair OBDII code P0139 in a 1998 Honda Civic?

- The cost of repair can vary depending on the specific issue, but it may range from $100 to $300 for parts and labor, excluding diagnostic fees.

9. Can a DIY enthusiast fix OBDII code P0139 in a 1998 Honda Civic?

- Depending on the skill level and tools available, a DIY enthusiast may be able to replace the oxygen sensor or address wiring issues, but more complex diagnostics may require professional help.

10. How often should the HO2S Bank 1 Sensor 2 be replaced in a 1998 Honda Civic?

- Oxygen sensors typically last around 100,000 miles, but it is advisable to follow the manufacturer's recommended maintenance schedule for optimal performance.