P0139 2005 Nissan Pathfinder 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 2005 Nissan Pathfinder 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.
Code P0139 2005 Nissan Pathfinder Description
What are the Possible Causes of the DTC P0139 2005 Nissan Pathfinder?
- 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 2005 Nissan Pathfinder?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0139 2005 Nissan Pathfinder 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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Frequently Asked Questions about P0139 2005 Nissan Pathfinder Code
1. What does OBDII code P0139 on a 2005 Nissan Pathfinder mean?
The code P0139 indicates a slow response from the downstream oxygen sensor (HO2S12) located after the catalytic converter.
2. What are some common symptoms of HO2S12 slow response in a 2005 Nissan Pathfinder?
Common symptoms of a slow response from the downstream oxygen sensor may include poor fuel economy, rough idling, engine misfires, and a noticeable decrease in overall vehicle performance.
3. What are the possible causes of OBDII code P0139 on a 2005 Nissan Pathfinder?
Potential causes of code P0139 include a faulty downstream oxygen sensor, wiring issues in the oxygen sensor circuit, exhaust leaks, a damaged catalytic converter, or an engine running too rich or too lean.
4. How can I diagnose the HO2S12 slow response issue on my 2005 Nissan Pathfinder?
To diagnose the slow response from the downstream oxygen sensor, you can use an OBDII scanner to retrieve the exact trouble code, visually inspect the sensor and its wiring for any damage, and perform a voltage test to check sensor operation.
5. Can I still drive my 2005 Nissan Pathfinder with OBDII code P0139?
It is generally not recommended to drive your vehicle with an unresolved HO2S12 slow response issue, as it can lead to further damage to the catalytic converter and other engine components. It's best to address the problem promptly.
6. How do I repair OBDII code P0139 on my 2005 Nissan Pathfinder?
Repairing code P0139 may involve replacing the downstream oxygen sensor (HO2S12), repairing any damaged wiring in the sensor circuit, addressing exhaust leaks, and ensuring proper engine performance to prevent the issue from reoccurring.
7. Can a DIY enthusiast fix OBDII code P0139 on a 2005 Nissan Pathfinder?
While some experienced DIY enthusiasts may be able to replace the downstream oxygen sensor and perform basic checks, diagnosing and repairing the underlying causes of a slow response from the sensor may require professional expertise and specialized tools.
8. How much does it cost to repair OBDII code P0139 on a 2005 Nissan Pathfinder?
The cost of repairing code P0139 can vary depending on the specific issue causing the slow response from the downstream oxygen sensor. Expenses may include the cost of a new sensor, labor charges, and any additional parts or repairs needed.
9. Will resetting the OBDII code P0139 on my 2005 Nissan Pathfinder make it go away permanently?
Simply resetting the trouble code without addressing the root cause of the slow response from the downstream oxygen sensor will likely result in the code reappearing once the vehicle is driven again. It is essential to diagnose and fix the underlying issue for a permanent solution.
10. How often should I have the downstream oxygen sensor checked on my 2005 Nissan Pathfinder to prevent OBDII code P0139?
Regular maintenance checks, particularly during scheduled service intervals, can help catch potential issues with the downstream oxygen sensor early on. It's advisable to have the sensor inspected as part of routine vehicle maintenance to prevent code P0139 and related problems.
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