AutoCodes – Nissan – P0139 2011 Nissan Altima Sedan

P0139 2011 Nissan Altima Sedan 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 2011 Nissan Altima Sedan 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 3,473

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 Apr 12, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2011 Nissan Altima Sedan 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 2011 Nissan Altima Sedan - HO2S12 Slow Response - AutoCodes.com — P0139 2011 Nissan Altima Sedan Code - HO2S12 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 2011 Nissan Altima Sedan?

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 2011 Nissan Altima Sedan?

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 2011 Nissan Altima Sedan 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 2011 Nissan Altima Sedan Code

1. What does the OBDII code P0139 on a 2011 Nissan Altima Sedan indicate?

The code P0139 in a 2011 Nissan Altima Sedan specifically refers to a fault with the HO2S12 sensor, indicating a slow response from the downstream oxygen sensor.

2. What are the common symptoms of a HO2S12 slow response fault in a 2011 Nissan Altima Sedan?

Common symptoms of a P0139 code in a 2011 Nissan Altima Sedan may include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated check engine light.

3. What are the potential causes of a P0139 code in a 2011 Nissan Altima Sedan?

Common causes of a P0139 code in a 2011 Nissan Altima Sedan include a faulty oxygen sensor, wiring issues, exhaust leaks, or problems with the engine's air-fuel mixture.

4. How can I diagnose a P0139 code in my 2011 Nissan Altima Sedan?

Diagnosing a P0139 code in a 2011 Nissan Altima Sedan involves using an OBDII scanner to retrieve the code, inspecting the HO2S12 sensor and its wiring for damage, and checking for any exhaust leaks.

5. Can I still drive my 2011 Nissan Altima Sedan with a P0139 code?

It is not recommended to drive a 2011 Nissan Altima Sedan with a P0139 code for an extended period, as it can lead to decreased fuel efficiency and potential damage to the catalytic converter.

6. How can I repair a P0139 code in my 2011 Nissan Altima Sedan?

Repairing a P0139 code in a 2011 Nissan Altima Sedan typically involves replacing the faulty HO2S12 sensor, repairing any wiring issues, fixing exhaust leaks, and ensuring the air-fuel mixture is correct.

7. How much does it cost to repair a P0139 code in a 2011 Nissan Altima Sedan?

The cost of repairing a P0139 code in a 2011 Nissan Altima Sedan can vary depending on the specific issue, but it may range from $100 to $300 for parts and labor.

8. Can I reset the check engine light after fixing a P0139 code in my 2011 Nissan Altima Sedan?

Yes, you can reset the check engine light after fixing a P0139 code in a 2011 Nissan Altima Sedan using an OBDII scanner or by disconnecting the car's battery for a few minutes.

9. How often does a P0139 code occur in a 2011 Nissan Altima Sedan?

The occurrence of a P0139 code in a 2011 Nissan Altima Sedan can vary depending on the vehicle's maintenance history, driving conditions, and overall health of the engine and emission control system.

10. Is it necessary to address a P0139 code immediately in a 2011 Nissan Altima Sedan?

It is recommended to address a P0139 code in a 2011 Nissan Altima Sedan promptly to prevent further issues with fuel efficiency, engine performance, and emissions.