P0432 Fault Code

Main Catalyst Efficiency Below Threshold (Bank 2)

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

• P0432 is a trouble code that indicates the Main Catalyst Efficiency Below Threshold specifically for Bank 2 of the engine.
• This code suggests that the catalytic converter is not functioning as efficiently as required, which can lead to increased emissions and reduced performance.
• Bank 2 typically refers to the side of the engine that does not contain cylinder number one in a V-type engine configuration.

What are the symptoms of the P0432 code?

• Poor engine performance, including a decrease in acceleration and power.
• Increased fuel consumption as the engine struggles to maintain efficiency.
• The vehicle may emit a noticeable odor of unburned fuel or rotten eggs from the exhaust system.
• The Check Engine Light (CEL) will likely illuminate, indicating a malfunction that needs attention.

What causes the P0432 code?

• A failing or damaged catalytic converter that cannot efficiently convert exhaust gases.
• Issues with oxygen sensors that may provide incorrect readings about the exhaust composition.
• Exhaust leaks affecting the sensor readings and causing incorrect efficiency calculations.
• Engine performance issues such as misfires can contribute to abnormal exhaust conditions that affect the catalyst.

How to fix P0432?

• Start diagnostics by scanning the vehicle’s computer to confirm the P0432 code and check for additional trouble codes.
• Inspect and, if necessary, replace faulty oxygen sensors before the catalytic converter.
• Check for exhaust leaks in the system, particularly near the catalytic converter and upstream from the oxygen sensors.
• If the catalytic converter is determined to be defective, replacing it will likely resolve the issue. Ensure that any related issues (like engine misfires) are corrected before replacing the cat to prevent recurrence.