P0139 Mitsubishi Code - Cylinder 1-4 Heated Oxygen Rear Sensor Circuit Slow Response
Quick Answer
The P0139 code for Mitsubishi vehicles indicates an issue with the Cylinder 1-4 Heated Oxygen Rear Sensor Circuit Slow Response. Common causes include Contaminated or damaged oxygen sensor, Faulty wiring or connectors, ECM issues. 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 Mitsubishi indicates Cylinder 1-4 Heated Oxygen Rear Sensor Circuit Slow Response.
- Common causes
- Common causes include Contaminated or damaged oxygen sensor, Faulty wiring or connectors, ECM issues.
- 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 P0139 Mitsubishi Description
The P0139 code for Mitsubishi vehicles indicates an issue with the Cylinder 1-4 Heated Oxygen Rear Sensor Circuit Slow Response. This means that the rear oxygen sensor, which is responsible for monitoring the exhaust gases and providing feedback to the engine control module (ECM), is not responding as quickly as expected. The oxygen sensor plays a crucial role in the engine's fuel management system by measuring the amount of oxygen in the exhaust gases and adjusting the air-fuel mixture accordingly.
Common Causes of P0139 Mitsubishi
- Contaminated or damaged oxygen sensor
- Faulty wiring or connectors
- ECM issues
- Exhaust leaks
- Incorrect air-fuel mixture
Symptoms of P0139 Mitsubishi
- Decreased fuel efficiency
- Poor engine performance or rough idling
- Illuminated Check Engine Light
- Failed emissions test
- Potential damage to the catalytic converter
How to Fix P0139 Mitsubishi
- Begin by diagnosing the issue using a scan tool to determine the specific cause of the slow oxygen sensor response.
- Inspect the oxygen sensor for any contamination or damage. Clean or replace the sensor if necessary.
- Check the wiring and connectors for any signs of damage or corrosion. Repair or replace as needed.
- Test the ECM to ensure it is functioning correctly. Replace if a fault is detected.
- Clear the diagnostic code and perform a test drive to verify that the issue has been resolved.
Cost to Fix P0139 Mitsubishi
The cost of repairing a P0139 code can vary depending on the specific cause of the issue and the labor rates in your area. In general, the parts for an oxygen sensor replacement can range from $50 to $200, while the labor cost can be between $100 and $200. Overall, the total repair cost for addressing a Cylinder 1-4 Heated Oxygen Rear Sensor Circuit Slow Response code is usually around $150 to $400. Keep in mind that additional costs may apply if other components need to be replaced or repaired. It is advisable to consult with a professional mechanic to get an accurate estimate based on your vehicle's make and model.
Tech Notes for P0139 Mitsubishi
When is the Code Detected?
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Frequently Asked Questions about P0139 Mitsubishi Code
1. What does the OBDII code P0139 mean for a Mitsubishi vehicle?
The code P0139 indicates a slow response from the heated oxygen sensor located downstream of the catalytic converter for cylinders 1-4.
2. What are the common symptoms of P0139 in a Mitsubishi?
Symptoms may include reduced fuel efficiency, engine hesitation, rough idling, and an illuminated check engine light.
3. What causes the P0139 code to appear in a Mitsubishi?
Common causes include a failing rear oxygen sensor, exhaust leaks, damaged wiring or connectors, or a degraded catalytic converter.
4. Can a dirty or clogged catalytic converter trigger the P0139 code?
Yes, a clogged catalytic converter can affect exhaust flow and oxygen sensor readings, potentially triggering a slow response error.
5. How can I diagnose the P0139 code on my Mitsubishi?
Use an OBDII scanner to confirm the code, inspect the rear oxygen sensor and its wiring, and check for exhaust leaks or catalytic converter issues.
6. Is it safe to drive a Mitsubishi with the P0139 code?
While it may be possible to drive, prolonged use can lead to poor fuel economy and potentially damage other components, so repairs should be made promptly.
7. How do I fix the P0139 code on my Mitsubishi?
Repair steps may include replacing the rear oxygen sensor, fixing any exhaust leaks, repairing damaged wires or connectors, or replacing the catalytic converter if needed.
8. How much does it cost to repair code P0139 on a Mitsubishi?
Costs vary depending on the issue, but replacing an oxygen sensor typically costs $150-$300, while catalytic converter repairs can be significantly more expensive.
9. Can a P0139 code be triggered by bad fuel quality?
Poor fuel quality can lead to incomplete combustion, which may affect oxygen sensor readings and potentially trigger this code.
10. How can I prevent the P0139 code from appearing on my Mitsubishi?
Perform regular maintenance, use high-quality fuel, promptly address exhaust leaks, and replace oxygen sensors as recommended by the manufacturer.
Discuss the causes and fixes for P0139 Mitsubishi OBDII Code
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Does this code relate to others. I got this code immediately after replacing the downstream o2 censor and the catalysted converter. I was shooting the p0420 and p0138 codes before I did those repairs. And the very next morning got the p0139 on my way to the emissions testing site.
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What model and year is your vehicle? The P0139 code is for the dowstream O2 sensor as well. Double check the sensor connection and make sure there are no exhaust leaks.
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I have an 08 lancer (no turbo). It was taken to a shop for the previous repairs. Should it be something they’re responsible for? I only know how to drive cars.
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It's possible. There is only one rear Oxygen Sensor and both codes are for the same sensor.
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