AutoCodes – Nissan – P0139 2006 Nissan Maxima

P0139 2006 Nissan Maxima 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 Maxima 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 2,697

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 Maxima 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 Maxima - HO2S12 Slow Response - AutoCodes.com — P0139 2006 Nissan Maxima Code - HO2S12 Slow Response

What does this mean?

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

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 Maxima?

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 Maxima 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 Maxima Code

1. What are the common symptoms of OBDII code P0139 in a 2006 Nissan Maxima?

- Common symptoms include poor fuel efficiency, rough idling, engine misfires, and the illumination of the Check Engine Light.

2. What does the OBDII code P0139 for a 2006 Nissan Maxima indicate?

- The code P0139 indicates that the downstream oxygen sensor (HO2S12) is experiencing a slow response or is not functioning properly.

3. What are the possible causes of the HO2S12 slow response code in a 2006 Nissan Maxima?

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

4. How can I diagnose the cause of the HO2S12 slow response code in my 2006 Nissan Maxima?

- Diagnosis typically involves checking the oxygen sensor's wiring, inspecting for exhaust leaks, testing the sensor's functionality, and ensuring proper fuel system operation.

5. Can a dirty or contaminated oxygen sensor cause the P0139 code in a 2006 Nissan Maxima?

- Yes, a dirty or contaminated oxygen sensor can contribute to a slow response and trigger the P0139 code in your Nissan Maxima.

6. What is the recommended repair for OBDII code P0139 in a 2006 Nissan Maxima?

- The recommended repair often involves replacing the downstream oxygen sensor (HO2S12) to address the slow response issue and clear the code.

7. Is it safe to continue driving my 2006 Nissan Maxima with the P0139 code?

- While the vehicle may still be operable, it is recommended to address the underlying issue causing the code to prevent potential damage to the catalytic converter and ensure optimal engine performance.

8. Can a DIY enthusiast easily replace the downstream oxygen sensor in a 2006 Nissan Maxima?

- Yes, replacing the downstream oxygen sensor is considered a moderately challenging DIY repair that requires basic tools and some mechanical knowledge.

9. How can I prevent the OBDII code P0139 from recurring in my 2006 Nissan Maxima after repair?

- To prevent code recurrence, ensure proper installation of the new oxygen sensor, address any underlying issues such as exhaust leaks, and perform regular maintenance on the vehicle's fuel system.

10. Will resetting the Check Engine Light after replacing the oxygen sensor clear the P0139 code in a 2006 Nissan Maxima?

- Yes, resetting the Check Engine Light after replacing the oxygen sensor will clear the P0139 code, but the code may return if the underlying issue is not fully resolved.