Engine-Codes.com
Engine-Codes – Infiniti – P0139 2004 Infiniti G35

P0139 2004 Infiniti G35 Code - HO2S12 Slow Response

Quick Answer

The P0139 code for a 2004 Infiniti G35 indicates a slow response from the downstream oxygen sensor (HO2S12). Common causes include Contaminated or damaged oxygen sensor, Wiring or connector issues, Exhaust leaks. 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 2004 Infiniti G35 indicates HO2S12 Slow Response.
Common causes
Common causes include Contaminated or damaged oxygen sensor, Wiring or connector issues, Exhaust leaks.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 11, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0139 2004 Infiniti G35 Description

The P0139 code for a 2004 Infiniti G35 indicates a slow response from the downstream oxygen sensor (HO2S12). The oxygen sensor is responsible for measuring the oxygen content in the exhaust gases and providing feedback to the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion. A slow response from the oxygen sensor can lead to inefficient fuel combustion, reduced engine performance, and increased emissions.

OBDII Code P0139 2004 Infiniti G35 - HO2S12 Slow Response
P0139 2004 Infiniti G35 Code - HO2S12 Slow Response

Common Causes of P0139 2004 Infiniti G35

  1. Contaminated or damaged oxygen sensor
  2. Wiring or connector issues
  3. Exhaust leaks
  4. Faulty ECM
  5. Exhaust system damage

Symptoms of P0139 2004 Infiniti G35

  1. Check engine light illuminated
  2. Reduced fuel efficiency
  3. Rough idling or stalling
  4. Engine misfires
  5. Increased emissions

How to Fix P0139 2004 Infiniti G35

  1. Begin by connecting a diagnostic scanner to the vehicle's OBD-II port to retrieve the trouble code and confirm the issue.
  2. Inspect the oxygen sensor and its wiring for any signs of damage or contamination. Replace the sensor if necessary.
  3. Check for exhaust leaks and repair any leaks found in the system.
  4. Clear the trouble code from the ECM's memory with the diagnostic scanner and test drive the vehicle to ensure the issue has been resolved.
  5. If the problem persists, further diagnostics may be needed to identify any underlying issues with the ECM or other components.

Cost to Fix P0139 2004 Infiniti G35

The cost of repairing a P0139 code on a 2004 Infiniti G35 can vary depending on the specific cause of the issue. Typically, the cost of a new downstream oxygen sensor can range from $50 to $200, depending on the brand and quality. Labor costs for sensor replacement can range from $100 to $200, depending on the shop's hourly rates and the location of the sensor. Overall, the total repair cost for addressing a P0139 code can range from $150 to $400, but it's important to get a detailed quote from a reputable auto repair shop for a more accurate estimate. Labor rates can vary based on location, vehicle make and model, and the complexity of the repair.

What does this mean?

Tech Notes for P0139 2004 Infiniti G35

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

When is the Code Detected?

The P0139 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor takes more time to respond between rich and lean than the specified time.

Need more information about the P0139 2004 Infiniti G35 code?

Need more information on how to fix the P0139 2004 Infiniti G35 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0139 2004 Infiniti G35 code diagnosed by a professional: Find a repair shop in your area

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 2004 Infiniti G35 Code

1. What does OBDII code P0139 in a 2004 Infiniti G35 indicate?

This code, HO2S12 Slow Response, specifically points to a slow response from the oxygen sensor located downstream of the catalytic converter in bank 1.

2. What are the common symptoms of OBDII code P0139 in a 2004 Infiniti G35?

Common symptoms include poor fuel economy, rough idling, engine hesitation, and potentially an illuminated check engine light on the dashboard.

3. What are the possible causes of OBDII code P0139 in a 2004 Infiniti G35?

Potential causes include a faulty oxygen sensor, wiring issues in the sensor circuit, exhaust leaks, or issues with the catalytic converter.

4. How can I diagnose the source of OBDII code P0139 in my 2004 Infiniti G35?

Diagnosing this code typically involves checking the oxygen sensor's wiring and connections, inspecting the sensor for damage, and using a scan tool to monitor sensor data for proper operation.

5. Can I still drive my 2004 Infiniti G35 with OBDII code P0139 present?

While driving with this code may be possible, it is recommended to address the issue promptly to prevent potential damage to the catalytic converter and ensure optimal engine performance.

6. How do I repair OBDII code P0139 in my 2004 Infiniti G35?

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

7. Is it possible to reset the check engine light after fixing OBDII code P0139 in a 2004 Infiniti G35?

Yes, once the underlying issue causing the code has been resolved, the check engine light can be reset using an OBDII scan tool to clear the code from the vehicle's memory.

8. How much does it typically cost to fix OBDII code P0139 in a 2004 Infiniti G35?

The cost of repairs for this code can vary depending on the specific issue, but it may range from around $100 for a new oxygen sensor to several hundred dollars for more complex repairs involving the catalytic converter.

9. Can I prevent OBDII code P0139 from occurring in my 2004 Infiniti G35?

Regular maintenance, such as replacing oxygen sensors at recommended intervals and addressing any exhaust system issues promptly, can help prevent this code from appearing in the future.

10. How long does it take to repair OBDII code P0139 in a 2004 Infiniti G35?

The repair time can vary based on the exact cause of the code and the complexity of the fix, but it typically takes a few hours to a full day to diagnose and repair the issue.

Discuss the causes and fixes for P0139 2004 Infiniti G35 OBDII Code

Submit a New Comment

Code P0139 2004 Infiniti G35 comments

No comments found for this page.