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P0145 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


Trouble codes, which are essential indicators of potential problems in vehicles’ systems, play a major role in automotive diagnostics. One such code related to the Oxygen Sensor Circuit Slow Response for Bank 1 Sensor 3 is P0145 DTC Diagnostic Trouble Code. In order to maintain the performance of your car and diagnose all problems properly, you have to understand why P0145 is important and what its effects are.


In particular, the P0145 code indicates that in the Oxygen Sensor O2 circuit for Bank 1 Sensor 3, there is a slow response condition. The O2 sensor will be responsible for monitoring the oxygen content of exhaust gases after they have been removed from the engine. To adjust the mixture of air-fuel and optimize engine performance, this information is important to the Engine Control Module (ECM).


The P0145 error code may appear for several reasons:

  • Faulty Oxygen Sensor: The O2 sensor may be faulty, providing delayed or slow response readings to the ECM.
  • Wire Issues: Corroded or damaged wire that connects the O2 sensor to the ECM might impede signals and reduce reaction time.
  • Connector problems: The transmission between the O2 sensor and the ECM may be hampered by loose or damaged connectors.
  • Exhaust System Leaks: Any leaks in the exhaust system that are located before the O2 sensor might slow down sensor readings.
  • ECM Malfunction: The P0145 error code can occasionally be caused by the Engine Control Module itself.


You may notice a number of symptoms when the P0145 code is activated that point to possible problems with your car:

  • Illuminated Check Engine Light: The most apparent sign of a trouble code, the check engine light is activated.
  • Decreased Engine Performance: Delays in adjusting the air-fuel mixture may cause the engine to run with less power, hesitate, or idle rough.
  • Higher Emissions: A vehicle may fail emission tests as a result of slow O2 sensor response, which can result in higher emissions.


A methodical strategy is needed to correctly identify the P0145 code’s root cause. The following diagnostic procedures can be carried out by a skilled mechanic or an OBD-II scanner:

  • Checking for Codes: The P0145 code is read and retrieved from the vehicle’s ECM using an OBD-II scanner.
  • Visual Inspection: To find any obvious problems, the O2 sensor’s wiring and connections must be thoroughly inspected visually.
  • Testing the Oxygen Sensor: A multimeter should be used to test the voltage output and reaction time of the sensor to determine how well it is working.
  • Examining the Exhaust System for Leaks: The technician will look for any leaks that could be impacting the O2 sensor’s performance.

Common mistakes

Some typical errors can happen during diagnostics and repairs, resulting in inaccurate or inefficient fixes:

  • Ignoring wire and Connectors: A loose connector or broken wire is frequently the cause of problems but is frequently disregarded.
  • Replacing the oxygen sensor without testing: Before contemplating a replacement, the sensor’s functionality and reaction time must be thoroughly tested.
  • Ignoring Exhaust System Leaks: Since exhaust system leaks might impair O2 sensor responsiveness and readings, they should be fixed.

How serious is this?

The seriousness of the P0145 code depends on a variety of factors. Although this may be a slight inconvenience, it can result in engine performance problems and higher emissions if the problem is not resolved. It is recommended to diagnose and fix the problem as soon as possible, with a view to avoiding additional complications.

What repairs can fix the code?

repair manuals

The following remedies can be made if the P0145 code’s underlying cause has been found:

  • Oxygen Sensor Replacement: The sensor should be replaced with a suitable, high-quality component if it is malfunctioning or responding too slowly.
  • Fixing wires and connections: If required, damaged wires or connections should be fixed or replaced.
  • Repairing Exhaust Leaks: To stop the entry of outside air, any leaks in the exhaust system before the O2 sensor should be patched.

Related codes

Occasionally, other DTCs might accompany the P0145 code, providing additional insights into related issues. Commonly related codes include P0139 (Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2) and P0155 (Oxygen Sensor Heater Circuit Malfunction Bank 2 Sensor 1).


Finally, the P0145 DTC code indicates a potential problem with the slow response of the Oxygen Sensor circuit for Bank 1 Sensor 3. You may be able to effectively address this issue by understanding its meaning, causes, symptoms, and appropriate treatments. A quick diagnosis and correct repair are not just going to clear this code, they’re also going to make your car operate in the best possible way, so you get a better driving experience. 

To ensure that your vehicle remains in excellent condition, it is always recommended that you seek the advice of a professional technician to diagnose accurately and secure any necessary repairs.

P0145 Code – What Does It Mean & How To Fix It