P0428 Fault Code

Catalyst Temperature Sensor High Input (Bank 1 Sensor 1)

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

The P0428 fault code indicates an issue with the Catalyst Temperature Sensor located in Bank 1, Sensor 1. This sensor monitors the temperature of the catalytic converter to ensure it is functioning within specified limits. A high input from this sensor can lead to inefficiencies in the emissions control system, potentially increasing harmful exhaust emissions.

What are the symptoms of the P0428 code?

When experiencing a P0428 code, you may notice:

• Check Engine Light illuminated on the dashboard.
• Increased emissions, possibly leading to failed emissions tests.
• Changes in engine performance, such as reduced power or efficiency.
• In some cases, unusual scents or odors from the exhaust may be present.

What causes the P0428 code?

There are several potential causes for the P0428 code, including:

• Faulty catalyst temperature sensor, which may be sending incorrect readings.
• Damaged wiring or poor connections leading to overvoltage or short circuits.
• Issues with the engine's exhaust system, such as leaks positioned before the sensor.
• Problems within the engine management system that could affect sensor operation.

How to fix P0428?

To resolve the P0428 fault code, it is recommended to:

• Inspect the catalyst temperature sensor for any signs of damage or wear.
• Check all wiring and connectors for frayed edges or poor connections; repair or replace as necessary.
• Ensure there are no exhaust leaks in the flow path that could affect readings.
• If the sensor is faulty, replacing it should clear the code and restore normal operation.