P0142 Fault Code

O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0142 code indicates a malfunction in the oxygen sensor circuit for Bank 2 Sensor 3. This sensor plays a crucial role in monitoring exhaust gases to ensure optimal engine performance and emissions control. If the vehicle's computer detects an issue with this sensor, it triggers the code, which can lead to decreased fuel efficiency and increased emissions.

• Oxygen sensors are essential for adjusting the air-fuel mixture in the engine.
• A malfunction may cause the engine to run rich or lean, affecting performance and emissions.
• This sensor is typically located after the catalytic converter in the exhaust system.

What are the symptoms of the P0142 code?

Vehicles with a P0142 code may exhibit the following symptoms:

• Illuminated check engine light on the dashboard
• Decreased fuel efficiency due to incorrect air-fuel mixture
• Increased emissions leading to failing an emissions test
• Rough idling or stalling if the sensor is significantly malfunctioning
• Poor acceleration or engine performance issues

What causes the P0142 code?

Several factors can trigger the P0142 code, including:

• A faulty oxygen sensor itself
• Wiring issues, such as frayed or corroded connectors
• Poor electrical connections or shorts in the circuit
• Exhaust leaks near the sensor, which can lead to false readings
• Problems with the engine control module (ECM) affecting sensor readings

How to fix P0142?

To resolve the P0142 code, the following steps may be undertaken:

• Use an OBD-II scanner to confirm the code and check for any additional codes.
• Inspect the oxygen sensor and its wiring for damage or corrosion.
• Replace the oxygen sensor if it is found to be faulty.
• Repair any broken wiring or connections that may affect the sensor's operation.
• Clear the code and conduct a test drive to ensure the issue is resolved and the check engine light does not return.