AutoCodes – Honda – P0139 1999 Honda Civic

P0139 1999 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 1999 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 6,150

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 1999 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 1999 Honda Civic - HO2S Bank 1 Sensor 2 Slow Response - AutoCodes.com — P0139 1999 Honda Civic Code - HO2S Bank 1 Sensor 2 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 1999 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 1999 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 1999 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 1999 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 1999 Honda Civic Code

1. What are the common symptoms of OBDII code P0139 on a 1999 Honda Civic?

- Common symptoms include poor fuel economy, rough idling, and a noticeable decrease in engine performance.

2. What does the OBDII code P0139 "HO2S Bank 1 Sensor 2 Slow Response" mean for a 1999 Honda Civic?

- This code indicates that the oxygen sensor downstream of the catalytic converter in bank 1 is not responding as quickly as expected.

3. What are the possible causes of OBDII code P0139 on a 1999 Honda Civic?

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

4. How can I diagnose the OBDII code P0139 on my 1999 Honda Civic?

- To diagnose this code, you can use an OBDII scanner to retrieve the code and then inspect the oxygen sensor, wiring connections, and exhaust system for any visible issues.

5. Can I continue driving my 1999 Honda Civic with the OBDII code P0139?

- It is not recommended to drive with this code unresolved, as it can lead to decreased fuel efficiency and potential damage to the catalytic converter over time.

6. How can I repair OBDII code P0139 on my 1999 Honda Civic?

- Repair options may include replacing the oxygen sensor, repairing any damaged wiring, fixing exhaust leaks, or replacing the catalytic converter if necessary.

7. Are there any DIY tips for resolving OBDII code P0139 on a 1999 Honda Civic?

- DIY tips may include checking and cleaning the oxygen sensor connections, inspecting the wiring for damage, and ensuring there are no exhaust leaks.

8. How much does it typically cost to fix OBDII code P0139 on a 1999 Honda Civic?

- The cost of repairs for this code can vary depending on the specific issue, but it may range from $100 to $500 or more, including parts and labor.

9. Can a bad fuel injector cause OBDII code P0139 on a 1999 Honda Civic?

- While a bad fuel injector is not a common cause of this specific code, it can contribute to related symptoms like poor fuel economy and rough idling.

10. How often should the oxygen sensor be replaced in a 1999 Honda Civic to prevent OBDII code P0139?

- Oxygen sensors typically last around 60,000 to 90,000 miles, so it is recommended to replace them within this mileage range to prevent issues like code P0139.