Your vehicle’s check engine light will usually illuminate once its powertrain control module (PCM) detects an issue with any of your engine components. But how would you know which component is causing the issue?
Modern vehicles are equipped with on-board diagnostic (OBD) systems to give you or a mechanic a starting point for further troubleshooting. P0144 is just one of the many OBD-II codes related to a possible issue in the oxygen sensor circuit.
What Does the P0144 Code Mean?
Diagnostic Trouble Code (DTC) P0144 stands for “O2 Sensor Circuit High Voltage (Bank 1 Sensor 3).” It is logged once the PCM perceives that the voltage signal in the oxygen sensor (sensor 3) located in bank 1 is too high.
The code points to the post-cat sensor located in bank 1. This sensor is located behind the catalytic converter or cat-con and monitors the amount of oxygen in the exhaust. Readings from this sensor are compared with data from pre-cat con sensors to determine the converter’s efficiency in reducing emissions.
It’s important to ensure that your engine’s cat-con is working as it should. Aside from increasing harmful emissions, a faulty converter can cause engine issues that may eventually lead to poor engine performance.
An oxygen sensor sends data to the PCM through voltage signals. The signals vary depending on the amount of oxygen in the exhaust. Once the PCM perceives that the voltage signal is too high, it will trigger this trouble code.
If you’re planning to resolve the issue yourself, read our technical explanation about how the downstream oxygen sensor can cause codes like P0144 to get more background information on the matter.
Note: The definition of code P0144 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
What are the Possible Causes of the P0144 Code?
Here are the possible triggers of a P0144 trouble code:
- Faulty oxygen sensor (bank 1, sensor 3)
- Wiring issues
- Rich running condition
- Faulty PCM or software in need of an update
What are the Common Symptoms of a P0144 Code?
Here are the common symptoms related to the P0144 code:
- Illuminated check engine light
- Decreased fuel efficiency
- Elevated tailpipe emissions
- Failed emission test
- Decreased engine power
How to Diagnose the P0144 Code
Diagnosing vehicle problems can prove complicated. If you don’t have sufficient auto repair know-how, it is best to take your vehicle to a mechanic. A professional would know how to properly diagnose an oxygen sensor circuit malfunction error code.
Alternatively, if you wish to troubleshoot this code on your own, we recommend getting a repair manual or an online repair database subscription. These resources can give you an idea of what the diagnostic procedures may entail.
How to Fix the P0144 Code
All modern vehicles come equipped with oxygen sensors. However, it doesn’t mean that repair steps for these sensors are the same across all makes and models. Remember that vehicle engines may be structured differently per manufacturer. For instance, repair steps that worked for a P0144 on a Ford Focus may not work for a P0144 on a Mazda 3.
The easiest way to resolve this code is to leave the job to a mechanic. However, if you’re a seasoned DIYer, we recommend consulting a vehicle-specific repair manual or subscribing to an online repair database. These resources contain helpful information about the repair procedures that might work for your specific vehicle.
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Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.