P0139 OBD Error Code: Problem & Solutions

<<See All OBD Codes

The P0139 is a generic code which would indicate that the O2 sensor for bank 1 sensor 2 has failed to have a voltage drop below .2 volts for 7 seconds during a deceleration fuel cut off. Because of this failure, the engine control module would determine that the sensor response is too slow.

It is with the help of powertrain control module that the fuel is cut to the engine upon deceleration, and the O2 sensors should respond accordingly by a voltage output lower than 0.2V, showing exhaust stream as high in O2 content. This code would be triggered if the O2 sensor for Bank 1 sensor 2 does not respond to the fuel cut off within 7 seconds.

What causes this problem with the 02 Sensor Circuit Slow Response (Bank 1 Sensor 2)?

• The engine control module might cut all fuel to the engine during deceleration of the engine and the O2 sensors all should respond with a voltage output below .2 volts showing the exhaust stream is high in oxygen content. The code would start appearing if the O2 sensor for bank 1 sensor 2 does not respond to the fuel cut off for 7 seconds or more
• The reason behind the triggering up of this code can be by excessive fuel still in the exhaust stream from possible leaking in the fuel injection system

1. Oxygen Sensor - There can be some issues with the Oxygen Sensor due to which you may see P0139 code appearing over and over again. Visit us to buy best quality Oxygen Sensor online.
2. Mass Air Flow Sensor - Are you facing some faults in your Mass Air Flow Sensor? Don’t worry and get them replaced or else P0139 code can turn up.
3. Manifold Absolute Pressure sensor - Common cause behind this P0139 error code can be some fault in Manifold Absolute Pressure sensor. So, it will be a good decision to replace them now.
4. Exhaust Parts - Mass Air Flow Sensor is perfectly fine but still but having that trouble code P0139 flashing? In such a situation your Exhaust parts might be faulty. Why don’t you think of getting that replaced?
5. Powertrain Control Module - OBD Code P0139 can flash if the Powertrain Control Module is damaged. You must replace it with a brand new one online with us.
6. Engine Control Module - Is your Exhaust System perfectly correct, but still seeing P0139 code? Then there is definitely some issue with the Engine Control Module.
7. Fuel Pump - Did your mechanic just found out that there is some fault in the Fuel Pump? Buy top notch Fuel Pump from us at economical prices.

It is very important to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P0139 here:

Common Symptoms

• The car engine may start stalling or run roughly on deceleration if excessive fuel is getting in the engine
• The check engine light would start appearing
• The engine may hesitate upon acceleration after a deceleration phase

Learn the ways with which you can correct this trouble code:

• The O2 sensor for bank 1 sensor 2 should be replaced
• You can always repair or replace the wiring or connection to the oxygen sensor for bank 1 sensor 2
• The exhaust leaks or a damaged catalyst should be properly repaired

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of catalytic converter, fuel pump, relay wiring harness and many more. Now all your problems would vanish within no time.

• Scan the codes and documents freeze frame data
• The oxygen sensor data should be monitored to see if the voltage is dropping to below .2 volts during deceleration
• Carefully inspect the engine fuel pressure for a leaking fuel injector
• Check that the oxygen sensor is not contaminated with coolant or oil on the outside
• The integrity of the exhaust system should be verified for any problems with the catalyst
• The manufacturer's specific pinpoint tests should be followed for further diagnosis

Common Mistakes When Diagnosing The P0139 Code

Here are some simple guidelines which you should follow to prevent misdiagnosis

• If there is a slow response of the sensor, then it can be caused by a leaking fuel injector on bank 1 of the engine if both sensors 1 and 2 on that side are having the same problem
• A stuck-open throttle can stop the fuel cut off phase and make sure that it is fixed before this code