AutoCodes – Generic – P0432

P0432 Code - Main Catalyst Efficiency Below Threshold Bank 2

Quick Answer

The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor). Common causes include Warm Up Three Way Catalytic converter deterioration or malfunction, Exhaust system leaks, Loose front or rear HO2Ss. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0432 indicates Main Catalyst Efficiency Below Threshold Bank 2.
Common causes: Common causes include Warm Up Three Way Catalytic converter deterioration or malfunction, Exhaust system leaks, Loose front or rear HO2Ss.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 36,748

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P0432 Description

The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.

OBDII Code P0432 - Main Catalyst Efficiency Below Threshold Bank 2 - AutoCodes.com — P0432 Code - Main Catalyst Efficiency Below Threshold Bank 2

What does this mean?

What are the Possible Causes of the DTC P0432?

Warm Up Three Way Catalytic converter deterioration or malfunction
Exhaust system leaks
Loose front or rear HO2Ss
Faulty front heater O2 sensor
O2 sensors harness is open or shorted
O2 sensors poor electrical connection

How to Fix the DTC P0432?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

As the code description implies the P0432 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0432 code is combined with other codes, try fixing the other codes first.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0432 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0432 code?

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Information for Specific Makes

P0432 Audi — Main Catalyst Efficiency Below Threshold Bank 2
P0432 Chrysler — Catalytic 2/1 Efficiency
P0432 Dodge — Catalytic 2/1 Efficiency
P0432 Jeep — Catalytic 2/1 Efficiency
P0432 Mercedes-Benz — Main Catalyst Efficiency Below Threshold Bank 2
P0432 Volkswagen — Main Catalyst Efficiency Below Threshold Bank 2

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.