P1139 Code - Long Term Fuel Trim Add. Fuel B2 System Too Rich
Quick Answer
The P1139 diagnostic trouble code indicates that the Long Term Fuel Trim Additive Fuel Bank 2 system is detecting a fuel mixture that is too rich. Common causes include Faulty oxygen sensor, Clogged fuel injectors, Vacuum leaks. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1139 indicates Long Term Fuel Trim Add. Fuel B2 System Too Rich.
- Common causes
- Common causes include Faulty oxygen sensor, Clogged fuel injectors, Vacuum leaks.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P1139 Description
The P1139 diagnostic trouble code indicates that the Long Term Fuel Trim Additive Fuel Bank 2 system is detecting a fuel mixture that is too rich. This means that there is an excess of fuel being delivered to the engine in relation to the amount of air, leading to an imbalance in the air-fuel ratio. This can result in poor fuel economy, reduced engine performance, increased emissions, and potential damage to the catalytic converter over time. The Long Term Fuel Trim Additive refers to the adjustment made by the engine control module to compensate for deviations from the ideal air-fuel ratio, and a consistently rich condition can indicate a problem with the fuel delivery system or sensors.
Common Causes of P1139
- Faulty oxygen sensor
- Clogged fuel injectors
- Vacuum leaks
- Malfunctioning mass airflow sensor
- Issues with the fuel pressure regulator
Symptoms of P1139
- Decreased fuel efficiency
- Rough idling or stalling
- Engine hesitation or misfires
- Strong gasoline odor from exhaust
- Illuminated check engine light
How to Fix P1139
- Diagnose the specific cause of the rich fuel mixture by checking the oxygen sensor readings, fuel injector operation, vacuum lines, and other relevant components.
- Replace any faulty oxygen sensor, fuel injectors, or other damaged parts contributing to the rich fuel condition.
- Clean or replace clogged fuel injectors to ensure proper fuel delivery.
- Repair any vacuum leaks or issues with the mass airflow sensor to correct the air-fuel ratio imbalance.
- Reset the engine control module and clear the trouble code to see if the issue has been resolved.
Cost to Fix P1139
The cost of repairing a P1139 code can vary depending on the specific cause of the issue and the labor rates in your area. On average, you can expect to pay between $200 and $500 for parts and labor. Keep in mind that diagnostic time and labor rates at auto repair shops can differ, so it's best to get a quote from a trusted mechanic before proceeding with the repair.
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Code P1139 Information for Specific Makes
- P1139 Audi — Long Term Fuel Trim Add. Fuel B2 System Too Rich
- P1139 BMW — O2 Sensor Heater Circuit High Voltage Bank 1 Sensor 2
- P1139 Buick — HO2S Insufficient Switching Bank 1 Sensor 2
- P1139 Cadillac — HO2S Insufficient Switching Bank 1 Sensor 2
- P1139 Chevrolet — HO2S Insufficient Switching Bank 1 Sensor 2
- P1139 Ford — Water In Fuel Indicator Circuit Malfunction
- P1139 GMC — HO2S Insufficient Switching Bank 1 Sensor 2
- P1139 MINI — O2 Sensor Heater Circuit High Voltage Bank 1 Sensor 2
- P1139 Subaru — Front Oxygen A/F Sensor #1 Heater Circuit Performance/Range Problem
- P1139 Volkswagen — Long Term Fuel Trim Add. Fuel B2 System Too Rich
Frequently Asked Questions about P1139 Code
1. What are the common symptoms of OBDII code P1139?
- Common symptoms include decreased fuel efficiency, rough idling, engine misfires, and a strong smell of fuel from the exhaust.
2. What are some possible causes of OBDII code P1139?
- Potential causes include a faulty oxygen sensor, vacuum leaks, fuel pressure regulator issues, clogged fuel injectors, or a malfunctioning mass airflow sensor.
3. How can I diagnose the cause of OBDII code P1139?
- Diagnosing the issue may involve checking the oxygen sensor readings, inspecting for vacuum leaks, testing fuel pressure, examining fuel injector performance, and verifying the mass airflow sensor function.
4. Is it safe to continue driving with OBDII code P1139?
- It is not recommended to drive with this code unresolved, as it can lead to poor engine performance and potential damage to the catalytic converter over time.
5. Can I repair OBDII code P1139 myself?
- Depending on your mechanical skills and tools available, repairs for this code may range from simple tasks like replacing an oxygen sensor to more complex procedures involving fuel system diagnostics.
6. How much does it typically cost to fix OBDII code P1139?
- The cost of repairs for this code can vary widely depending on the specific cause, parts needed, and labor rates, but it may range from a few hundred to over a thousand dollars.
7. Will resetting the OBDII code P1139 resolve the issue?
- Simply resetting the code will not fix the underlying problem causing P1139. It is crucial to diagnose and address the root cause to prevent the code from reappearing.
8. Can a dirty air filter trigger OBDII code P1139?
- A dirty air filter can impact the air-fuel mixture but is unlikely to directly trigger P1139. However, maintaining a clean air filter is essential for overall engine performance.
9. How important is it to address OBDII code P1139 promptly?
- It is crucial to address this code promptly to ensure optimal engine performance, fuel efficiency, and emissions compliance while preventing potential damage to engine components.
10. Is it necessary to have a professional mechanic clear OBDII code P1139 after repairs?
- While not necessary, having a professional mechanic clear the code after repairs can ensure that the issue has been correctly addressed and verify that the code does not reappear.
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