P0136 Oxygen sensor circuit malfunction (Bank 1, Sensor 2)

P0136 – OBD-II Trouble Code Technical Description

Trouble code P0136 indicates a fault in the oxygen sensor 2 (bank 1) circuit.

What does the fault code mean P0136?

Trouble code P0136 indicates a problem with the downstream oxygen (O2) sensor (commonly referred to as the bank 2 O1 sensor, sensor 2). This code indicates that the engine control module (ECM) has detected too high a resistance in the oxygen sensor circuit or the oxygen sensor signal has remained persistently high for too long.

Possible reasons

Here are some of the possible causes of the P0136 trouble code:

• Defective oxygen sensor (O2).
• The wiring or connectors connecting the oxygen sensor to the engine control module (ECM) may be damaged or broken.
• Poor contact in the oxygen sensor connector.
• Problems with power or ground of the oxygen sensor.
• Malfunction of the catalyst or problems with the exhaust system.

Failures in these components can cause the oxygen sensor to malfunction, causing the P0136 code to appear.

What are the symptoms of a fault code? P0136?

Symptoms for DTC P0136 may vary depending on the specific vehicle and other factors:

• Unstable engine: Rough operation or instability of the engine when idling may be noticed.
• Increased fuel consumption: This may be caused by an incorrect air/fuel ratio due to a faulty oxygen sensor.
• Loss of power: The vehicle may experience a loss of power when accelerating or increasing speed.
• Frequent engine stops: Incorrect operation of the oxygen sensor may cause frequent engine shutdowns or engine restarts.
• Deteriorated environmental compliance: A malfunctioning oxygen sensor may result in increased emissions of harmful substances, which may result in unsatisfactory emission readings on inspection.

These symptoms can occur in varying degrees and may be related to other problems in the car, so it is always recommended to carry out diagnostics to pinpoint the cause.

How to diagnose a fault code P0136?

To diagnose DTC P0136, follow these steps:

1. Checking wires and connectors: Check the wires and connectors connecting the oxygen sensor to the vehicle's electrical system for damage, corrosion, or breaks.
2. Oxygen sensor test: Use a multimeter to check the resistance and voltage at the oxygen sensor. Make sure the oxygen sensor is functioning correctly and is producing the correct readings.
3. Checking the operation of the intake system: Check for leaks in the air intake system. Leaks can result in incorrect air-fuel ratios and erroneous oxygen sensor readings.
4. Checking the catalytic converter: Check the condition of the catalytic converter for damage or blockage. A damaged or clogged catalytic converter can cause the oxygen sensor to not function properly.
5. Checking the engine management system (ECM): Diagnose the engine management system to identify possible problems with software or other components that could cause the P0136 code.
6. Checking oxygen sensors of other banks (if applicable): If your vehicle is equipped with oxygen sensors on multiple banks (such as V-twins or side-by-side engines), ensure that the oxygen sensors on the other banks are working correctly.

After diagnosing and identifying the cause of the P0136 trouble code, you can begin the necessary repairs or replacement of parts. If you do not have experience diagnosing automotive systems, it is recommended that you contact a qualified auto mechanic.

Diagnostic errors

When diagnosing DTC P0136, the following errors may occur:

• Incorrect oxygen sensor diagnosis: Incorrect interpretation of oxygen sensor test results may result in incorrect diagnosis. It is necessary to correctly evaluate the sensor readings and make sure that it is working correctly.
• Ignoring other problems: Sometimes the P0136 code can be a result of other problems, such as intake system leaks or problems with the catalytic converter. Ignoring these problems can lead to incorrect diagnosis and replacement of unnecessary parts.
• Incorrect cause identification: Some mechanics may immediately jump to the conclusion that the oxygen sensor needs to be replaced without conducting a full diagnosis. This may result in replacing a faulty part and not addressing the root cause of the problem.
• Insufficient checking of wires and connectors: Incorrect wiring or connectors may cause erroneous oxygen sensor readings. They must be carefully checked for damage, corrosion or breaks.
• No software updates: In some cases, a software update in the Engine Control Module may be required to resolve the P0136 problem. You must ensure that the latest version of the software is installed.

To avoid these errors, it is important to conduct a complete and thorough diagnosis, taking into account all possible causes and factors affecting the operation of the oxygen sensor and engine management system. If you do not have experience diagnosing automotive systems, it is recommended that you contact a qualified auto mechanic.

How serious is the fault code? P0136?

Trouble code P0136, which indicates a faulty oxygen (O2) sensor in bank 1 bank 2, is quite serious because the oxygen sensor plays a key role in regulating the fuel-air mixture, which affects engine efficiency and emissions. If the problem persists, it may result in decreased engine performance, increased fuel consumption, and increased emissions. Therefore, it is recommended to resolve the cause of the P0136 code as soon as possible to avoid further problems with the vehicle.

What repair will help eliminate the code? P0136?

To resolve trouble code P0136, you must follow these steps:

1. Replacing the oxygen sensor: If diagnostics have confirmed that the oxygen sensor has indeed failed, then it should be replaced. Make sure the new sensor is compatible with your vehicle.
2. Checking Wiring and Connectors: Check the wiring and connectors connecting the oxygen sensor to the electronic engine control unit (ECU). Make sure the wiring is not damaged and the connections are secure.
3. Checking the catalyst: A faulty oxygen sensor can also be caused by a faulty catalytic converter. Check it for damage or blockages.
4. Software check: Sometimes the problem may be related to the software in the ECU. In this case, a firmware update or reprogramming may be required.
5. Additional diagnostics: If the problem does not resolve after replacing the oxygen sensor, additional diagnostics may be required on the fuel injection and ignition system, as well as other components that affect the operation of the oxygen sensor.

Contact a certified auto mechanic or auto repair shop for diagnosis and repair as correcting the P0136 code may require specialized equipment and experience.

Rear Oxygen Sensor Replacement P0136 HD | After Catalytic Converter Oxygen Sensor

P0136 – Brand-specific information

Deciphering the P0136 trouble code for some specific car brands:

1. Toyota / Lexus: Oxygen sensor (O2 sensor) No. 2, bank 1, open circuit
2. Honda/Acura: Oxygen sensor (O2 sensor) No. 2, bank 1, open circuit
3. Ford: No activity at oxygen sensor (O2 sensor) No. 2, bank 1
4. Chevrolet / GMC: No activity at oxygen sensor (O2 sensor) No. 2, bank 1
5. Nissan/Infiniti: Oxygen sensor (O2 sensor) No. 2, bank 1, open circuit
6. BMW/Mini: Catalyst, flow fault

Consult your specific vehicle's repair manual or service documentation for more specific information about the P0136 trouble code and what it means for your vehicle make.