P0146 OBD-II: O2 Sensor Circuit no Activity Detected

P0146 Severity

Moderate

Will P0146 go away on its own?

Once the vehicle's onboard system no longer detects the issue, most codes will disappear on their own. If your vehicle still has this code, however, it should be properly diagnosed to avoid a more serious problem.

For a proper diagnosis, RepairPal Certified shops have the equipment, tools, and expertise.

Moderate severity codes might not threaten the vehicle's safety or functionality immediately, but you should still get it diagnosed within a reasonable time frame to keep your car running well.

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What causes OBD-II fault code P0146?

The purpose of the oxygen sensor is to measure the oxygen content in the exhaust gases after they leave the combustion process of the engine. This information is critical to the PCM's ability to maintain efficient fuel economy. When the PCM detects a failure of the sensor or the information received from the sensor, it will set code P0146.

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Tuffy Tire & Auto Service Center - Grandview

4.7
(81)
2.39 mi
1524 W 5th Ave
Columbus, OH
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Excite Auto Repair & Towing

4.4
(15)
5.94 mi
3430 Westerville Road
Columbus, OH
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All In Auto Service

4.9
(22)
6.56 mi
5200 Fisher Road
Columbus, OH
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Closes 6:00 PM
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Tuffy Tire & Auto Service - Grove City

4.4
(520)
6.67 mi
2131 Stringtown Rd
Grove City, OH
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Closes 6:00 PM
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What Does P0146 Code Mean?

Fault Code Definition

The Rear Catalyst Monitoring Oxygen Sensor evaluates the rear most Catalytic Converter's emissions-reducing capability in a system with two Catalytic Converters for each bank of cylinders. P0146 is set when the Rear Oxygen Sensor signal does not show enough activity to indicate fuel control and closed loop fuel management

P0146 Symptoms

  • Check Engine Light will illuminate
  • In many cases, no abnormal symptoms may be noticed
  • In some cases, the vehicle will fail an Emissions Test
  • In many cases, the NOx emissions will be elevated

Common Problems That Trigger the P0146 Code

  • Defective Rear Most Oxygen Sensor
  • Faulty Rear Most Oxygen Sensor wiring or connections

Common Misdiagnoses

  • Oxygen Sensor is replaced when the problem is faulty sensor wiring or connections
  • Rear Catalytic Converter or Rear Oxygen Sensor is replaced when the problem is an exhaust leak before the Rear Oxygen Sensor
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