AutoCodes – Nissan – P0139 2007 Nissan Sentra

P0139 2007 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 2007 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 2,221

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 2007 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 2007 Nissan Sentra - HO2S12 Slow Response - AutoCodes.com — P0139 2007 Nissan Sentra Code - HO2S12 Slow Response

What does this mean?

What are the Possible Causes of the DTC P0139 2007 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 2007 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 2007 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 2007 Nissan Sentra Code

1. What does OBDII code P0139 mean on a 2007 Nissan Sentra?

- This code, HO2S12 Slow Response, indicates a slow response from the oxygen sensor 2 in bank 1 of the vehicle's exhaust system.

2. What are common symptoms of OBDII code P0139 on a 2007 Nissan Sentra?

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

3. What are the possible causes of OBDII code P0139 on a 2007 Nissan Sentra?

- The code P0139 on a 2007 Nissan Sentra can be triggered by issues such as a faulty oxygen sensor, wiring problems, exhaust leaks, or a damaged catalytic converter.

4. How can I diagnose the cause of OBDII code P0139 on my 2007 Nissan Sentra?

- To diagnose the issue, you can start by inspecting the oxygen sensor and its wiring for any visible damage. You can also check for exhaust leaks and perform a thorough inspection of the catalytic converter.

5. Can I still drive my 2007 Nissan Sentra with OBDII code P0139?

- It is not recommended to drive your Nissan Sentra with code P0139 for an extended period as it can lead to decreased fuel efficiency and potential damage to the catalytic converter.

6. How can I repair OBDII code P0139 on my 2007 Nissan Sentra?

- Repairing code P0139 may involve replacing the oxygen sensor, repairing any damaged wiring, fixing exhaust leaks, or replacing the catalytic converter if necessary.

7. Is it safe to reset the check engine light after fixing OBDII code P0139 on a 2007 Nissan Sentra?

- Yes, once you have repaired the underlying issue causing code P0139, it is safe to reset the check engine light using an OBDII scanner to clear the code.

8. How much does it typically cost to repair OBDII code P0139 on a 2007 Nissan Sentra?

- The cost of repairing code P0139 on a 2007 Nissan Sentra can vary depending on the specific issue, but it may range from $100 to $500 or more, including parts and labor.

9. Can a DIY enthusiast fix OBDII code P0139 on a 2007 Nissan Sentra?

- Depending on your skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair code P0139 themselves by following step-by-step guides or tutorials.

10. How often does OBDII code P0139 occur in a 2007 Nissan Sentra?

- Code P0139, indicating a slow response from the HO2S12 sensor, can occur sporadically or more frequently depending on the severity of the underlying issue and driving conditions.