P0146 Code: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)

Your vehicle’s check engine light usually illuminates once the vehicle’s powertrain control module (PCM) detects a possible issue. If you have a scan tool with you, you can connect it to your vehicle’s OBD port to retrieve the specific error code.

P0146 is an engine trouble code related to a possible issue in the oxygen sensor circuit. Read on to know more about this error code.

What Does the P0146 Code Mean?

Diagnostic trouble code (DTC) P0146 stands for “O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3).” It is logged when the PCM perceives that the oxygen sensor 3 in bank 1 is not responding as it should. It may also be logged once the PCM determines that the voltage variation is less than normal during a given period.

“Sensor 3” refers to the sensor located after the catalytic converter (post-cat). Its primary function is to monitor the efficiency of the vehicle’s catalytic converter. The PCM compares post-cat and pre-cat sensor readings to assess the efficiency of the cat-con.

Oxygen sensors dispatch signals to the PCM through voltage variations. A lean condition in the exhaust causes the supplied voltage to drop, while a rich condition in the exhaust causes the voltage to increase.

Once the PCM perceives that the oxygen sensor (bank 1, sensor 3) is not responding as it should or if it detects that the voltage variations are slower than usual for a specific amount of time, it will trigger the P0146 error code.

If you’re planning to fix P0146 yourself, you can get more information in our technical discussion about the downstream oxygen sensor.

Note: The definition of code P0146 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 P0146 Code?

Here are the possible triggers of the P0146 engine code:

• Faulty O2 sensor (bank 1, sensor 3)
• Wiring issue
• Faulty PCM

What are the Common Symptoms of a P0146 Code?

Here are the common symptoms associated with the P0146 code:

• Illuminated check engine light
• Engine idling
• Decreased fuel efficiency

How to Diagnose the P0146 Code

An oxygen sensor circuit malfunction may prove challenging to diagnose. Determining which wire, connector, or harness is causing the issue can be difficult, especially if you have limited knowledge and experience in auto repair.

However, if you’re an experienced DIYer who’d like to diagnose the issue yourself, we recommend consulting a repair manual or an online repair database. These resources will provide you with vehicle-specific troubleshooting and repair information.

How to Fix the P0146 Code

P0146 is a generic trouble code, which means it may appear on various makes and models. However, it doesn’t mean that there is one solution that would work for all vehicles.

For instance, repair steps that worked for a P0146 on a Nissan Altima may not work for a P0146 on a Nissan Rogue. This is because vehicle engines may be structured differently per make or model.

If you’re a seasoned DIYer, we recommend consulting vehicle-specific repair manuals. You may also subscribe to an online repair database to help you with your repairs.

Get a Replacement Oxygen Sensor Without Leaving Your Home

If a faulty oxygen sensor is triggering DTC P0146, you’ll need to replace it before the code can be cleared. Leaving the faulty oxygen sensor in place might lead to decreased fuel efficiency, which can put a hole in your wallet over time. Thankfully, you can easily buy a replacement oxygen sensor from CarParts.com.

The CarParts.com website is easy to navigate and was built with customer convenience in mind. It takes only a few quick clicks to find what you’re looking for from our vast catalog of parts. You can even filter parts to show oxygen sensors guaranteed to fit your vehicle. Once you find one you want, proceed through the secure checkout. Afterwards, all you need to do is wait. We’ll ship your new oxygen sensor to your doorstep in as fast as two business days.

Don’t let a faulty oxygen sensor jack up your fuel expenses. Get a new oxygen sensor without leaving the comforts of home by ordering from CarParts.com.

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