Code Definition

P0432 — Main Catalyst Efficiency Below Threshold (Bank 2)

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0432

P0432 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0432 is stored, the module has detected a signal or supply voltage lower than the expected operating range; and a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0432 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The engine control module (ECM) sets this code when it detects that the catalytic converter's efficiency on bank 2 is below the required threshold. This is determined by monitoring the oxygen sensor signals before and after the catalyst. If the post-catalyst sensor signal closely follows the pre-catalyst sensor signal, it indicates that the catalyst is not sufficiently reducing emissions.

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