AutoCodes – Nissan – P0139 2006 Nissan Sentra

P0139 2006 Nissan Sentra Code - HO2S12 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 2006 Nissan Sentra indicates HO2S12 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 3,457

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 Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2006 Nissan Sentra 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 2006 Nissan Sentra - HO2S12 Slow Response - AutoCodes.com — P0139 2006 Nissan Sentra Code - HO2S12 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 2006 Nissan Sentra?

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 2006 Nissan Sentra?

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 2006 Nissan Sentra 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 P0139 2006 Nissan Sentra Code

1. What does the OBDII code P0139 for a 2006 Nissan Sentra indicate?

The OBDII code P0139 for a 2006 Nissan Sentra, also known as HO2S12 Slow Response, indicates a slow response time from the downstream oxygen sensor (HO2S12) located after the catalytic converter.

2. What are the common symptoms of the P0139 code on a 2006 Nissan Sentra?

Common symptoms of the P0139 code on a 2006 Nissan Sentra include decreased fuel efficiency, rough idling, engine hesitation, and potential stalling.

3. What are the possible causes of the P0139 code on a 2006 Nissan Sentra?

Possible causes of the P0139 code on a 2006 Nissan Sentra include a faulty oxygen sensor (HO2S12), wiring issues in the sensor circuit, exhaust leaks, or a damaged catalytic converter.

4. How do I diagnose the P0139 code on my 2006 Nissan Sentra?

Diagnosing the P0139 code on a 2006 Nissan Sentra involves visually inspecting the oxygen sensor and its wiring, checking for exhaust leaks, and using a scan tool to monitor sensor data and response times.

5. Can I drive my 2006 Nissan Sentra with the P0139 code?

It is not recommended to drive your 2006 Nissan Sentra with the P0139 code for an extended period as it can lead to further damage to the catalytic converter and impact engine performance.

6. How can I repair the P0139 code on my 2006 Nissan Sentra?

To repair the P0139 code on a 2006 Nissan Sentra, you may need to replace the downstream oxygen sensor (HO2S12), repair any damaged wiring, fix exhaust leaks, or replace the catalytic converter if necessary.

7. Will resetting the trouble codes fix the P0139 code on my 2006 Nissan Sentra?

Resetting the trouble codes may temporarily clear the P0139 code on your 2006 Nissan Sentra, but if the underlying issue is not addressed, the code is likely to return.

8. How much does it cost to fix the P0139 code on a 2006 Nissan Sentra?

The cost to fix the P0139 code on a 2006 Nissan Sentra can vary depending on the specific issue causing the code, but it typically ranges from $100 to $500 for parts and labor.

9. Can a DIY enthusiast repair the P0139 code on a 2006 Nissan Sentra?

A DIY enthusiast with automotive repair experience may be able to replace the downstream oxygen sensor (HO2S12) to address the P0139 code on a 2006 Nissan Sentra, but diagnosing and fixing more complex issues may require professional help.

10. How often does the P0139 code occur in a 2006 Nissan Sentra?

The P0139 code for a 2006 Nissan Sentra can occur sporadically due to various factors, but it is important to address the issue promptly to prevent further damage to the vehicle's emissions system.