When encountering a treasured combination of errors on the dashboard or noticing unstable engine operation, car owners Nissan We often encounter the P0139 code (displayed as 0139 in some scanners). This is a signal of problems in the operation of the second oxygen sensor, located after the catalytic converter. Ignoring this warning may result in serious consequences for the engine and environmental systems.
The code indicates that the signal is from oxygen sensor (lambda probe) comes in too slowly or its voltage is outside the permissible limits. The engine control system detects incorrect operation catalyst or the sensor itself. It is important to understand that error 0139 does not always mean the need to immediately replace expensive parts; sometimes the problem lies in the wiring or the quality of the fuel.
Model owners Nissan Qashqai, X-Trail And Teana People often wonder how critical this malfunction is. If the car continues to drive, but with increased fuel consumption and rough idle speed, you have time for a quality diagnosis. However, there is no point in delaying a service visit or searching for the problem yourself, since failure of the catalyst is an expensive repair.
The essence of the fault code and the principle of operation of the sensors
To understand the nature of the error, it is necessary to understand how the fuel control system functions. The first oxygen sensor (Bank 1 Sensor 1) is responsible for adjusting the fuel mixture in real time, ensuring the optimal ratio of air and gasoline. The second sensor (Bank 1 Sensor 2), which causes error 0139, is located behind the catalyst and serves to monitor its efficiency.
This sensor compares the amount of oxygen in the exhaust gases before and after the converter. If the catalyst is working properly, it should reduce the oxygen level, and the signal from the second sensor will be stable, almost unchanged. When the signal begins to fluctuate as actively as from the first sensor, or its response slows down, the control unit records an error catalyst efficiency.
Error 0139 specifically indicates that the signal switching speed of the second lambda probe is too low. This means that the sensor does not have time to respond to changes in the composition of the exhaust, or the converter itself has ceased to perform its functions of cleaning gases. In some cases the problem may be related to injectors or an exhaust gas recirculation (EGR) system.
⚠️ Warning: If you notice a hydrogen sulfide (rotten egg) smell coming from your exhaust pipe along with an illuminated Check Engine light, this is a sign that the catalytic converter has already broken down and is clogging the exhaust system.
The main causes of the problem
There are several reasons why code 0139 can be generated. The most obvious is physical wear or failure of the oxygen sensor itself. Over time, the heating element inside the sensor may burn out, and the sensitive part may become contaminated with combustion products or antifreeze. This leads to the sensor no longer producing correct data.
An equally common cause is a violation of the integrity of the electrical circuit. Broken wiring, oxidation of contacts in connectors or a short circuit to ground can distort the signal entering the ECU. It is also worth checking the integrity catalyst - if its cells collapse and block the flow of exhaust gases, the pressure will change and the sensor will not be able to operate normally.
There are also indirect reasons related to engine operation. Problems with ignition system (spark plugs, coils), air leaks in the intake manifold or low-quality fuel can change the composition of the exhaust to such an extent that the catalyst cannot cope, and the sensor detects an anomaly. Often owners Nissan encounter this problem after using additives to clean the fuel system.
- 💊 Contamination or failure of the lambda probe heater.
- 💊 Break or short circuit in the wiring harness going to the sensor.
- 💊 Destruction of the ceramic honeycomb inside the catalytic converter.
- 💊 Incorrect voltage in the vehicle’s on-board network (problems with the generator).
Vehicle symptoms and behavior
How does the car behave when this error appears? In most cases, the driver notices minor changes in engine performance, which can easily be attributed to fatigue or poor fuel. However, with careful attention to detail, characteristic features can be identified. The car may begin to “triple”, especially at idle, when the load on the engine is minimal.
The increase in fuel consumption becomes noticeable. The ECU, not receiving correct data from the second sensor, goes into emergency mode and enriches the mixture, which leads to excessive consumption of gasoline. In addition, during acceleration there may be a loss of power, since the system cannot optimally adjust the ignition and injection phases without feedback from the catalyst.
Sometimes the car runs completely fine and the only sign of a problem is a light on Check Engine on the instrument panel. This is especially typical for the early stages of a breakdown, when the sensor is still functioning, but its response is already slow. In such cases, diagnosis without a scanner is impossible.
⚠️ Attention: If the error is accompanied by a flashing Check Engine light, this means that the misfire is so severe that it can damage the catalytic converter in no time. You must stop moving immediately.
- Up to 50,000 km
- 50,000 - 100,000 km
- 100,000 - 200,000 km
- More than 200,000 km
Diagnostics and testing of components
Before you run to the store for a new sensor, you need to conduct a thorough diagnosis. The first step is always a visual inspection. Open the hood, find the second lambda probe (it is located after the catalyst) and check the integrity of the wires. Breaks, melts or traces of oil on the connector are clear signs of a problem.
For a deeper analysis, you will need a multimeter or a professional scanner. It is necessary to check the resistance of the sensor heater. Typically it should be in the range from 2 to 14 Ohms, but it is better to check the exact values in the technical documentation for your model Nissan. If there is infinite or zero resistance, the heater has burned out.
The next step is checking the voltage signal. By connecting the scanner to the OBDII diagnostic connector, you can monitor the sensor operation graph in real time. The signal must be stable and change slowly. If the graph is a straight line or jumps erratically for no reason, this confirms a malfunction. Also worth checking supply voltage on the sensor connector, it must correspond to the rating of the on-board network.
☑️ Stages of diagnosing error 0139
Repair and replacement options
If diagnostics show that the problem is in the sensor, the only reliable solution is to replace it. Do not try to clean the lambda probe or restore contacts if they have oxidized - this is a temporary measure. For cars Nissan It is recommended to use original spare parts or high-quality analogues from trusted brands such as Denso or Bosch.
If the sensor is working and the error persists, the problem lies in the catalyst or control system. The destroyed catalyst must be removed and replaced with a new one, or a flame arrester with a lambda probe decoy (emulator) must be installed. The last option requires proper configuration of the ECU firmware so that error 0139 does not return.
Sometimes updating the engine control unit software helps. Manufacturers periodically release adjustments that change the algorithms for working with sensors. It is also worth checking and replacing the fuel filter if it has not been changed for a long time, as contaminated fuel can cause unstable operation.
- 🛠️ Replacement of the lambda probe with an original or high-quality analogue.
- 🛠️ Repair or complete replacement of the wiring harness in the exhaust system area.
- 🛠️ Installation of the catalyst emulator when removing it.
- 🛠️ Cleaning the air supply system and replacing the fuel filter.
Is it possible to drive without a catalyst?
You can drive without a catalyst, but this can lead to an exhaust odor in the cabin, increased noise and increased toxicity of exhaust gases. It is also illegal in some countries.
Table of codes and their decoding
To make it easier to understand the relationship between various errors that often occur with P0139, we provide a table. Understanding adjacent codes will help you more accurately determine the root of the problem. For example, P0135 often accompanies P0139 and indicates a faulty heater circuit.
| Error code | Description | Probable Cause |
|---|---|---|
| P0135 | Heater Circuit Malfunction (Bank 1 Sensor 1) | The heater of the first sensor burned out |
| P0139 | Slow response of oxygen sensor (Bank 1 Sensor 2) | Worn sensor or catalyst |
| P0420 | Low efficiency of the catalyst system | Catalyst destruction |
| P0130 | Oxygen sensor circuit malfunction (Bank 1 Sensor 1) | Broken wiring or sensor failure |
Before purchasing a new sensor, be sure to check the wire length and connector type, as they may differ even between identical Nissan models of different years of manufacture.
Exhaust system prevention and care
To avoid the appearance of error 0139 in the future, you must follow simple operating rules. Use only high-quality gasoline that meets the manufacturer's requirements. Cheap fuel with a high content of additives quickly damages both the catalyst and oxygen sensors.
Carry out regular vehicle maintenance. Timely replacement of spark plugs, coils and air filter prevents misfires, which can lead to overheating and destruction of the catalyst. If you hear strange sounds from the exhaust system, do not delay your service visit.
Avoid short trips with a cold engine. The lambda probe and catalyst require time to warm up and reach operating temperature. Frequent short trips do not give the system enough time to operate effectively, which accelerates component wear. Try to periodically warm up the engine and give it a load.
Regular diagnostics of the exhaust system and the use of high-quality fuel are the best ways to extend the life of the catalyst and avoid P0139 errors.
Frequently asked questions from owners
Below are answers to the most popular questions that owners have. Nissan when faced with this problem. These answers will help you make the right decision and save time.
Is it possible to remove error 0139 with a scanner and forget about it?
No, this is a temporary solution. If the fault is not physically corrected (the sensor or catalyst is not replaced), the error will return after several engine operating cycles. Resetting the code does not correct the cause of the problem.
How much does it cost to replace a lambda probe on a Nissan?
The cost depends on the car model and the selected part. The original can cost from 5,000 to 15,000 rubles, and a high-quality analogue can cost from 2,000 to 6,000 rubles. The work of a master usually costs 1000-2000 rubles.
Is error 0139 dangerous for the engine?
The error itself is not critical, but it can lead to improper engine operation, increased fuel consumption and, in the long term, destruction of the catalyst, which will entail expensive repairs.
Can I replace the sensor myself?
Yes, it is possible if you have the necessary tools (a special key for the lambda probe) and skills. However, it is important to be careful as the sensor may become stuck and there is a risk of damaging the threads or the catalyst itself.