P0431 Warm Up Catalyst Efficiency

Description and meaning of DTC p0431

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. Basically this means that the oxygen sensor downstream of the catalytic converteron bank 2 is detectingthat the converter is not working as efficiently as it should be (accordingto specs). It is part of the vehicle emissions system.

p0431 diagnostic trouble code symptoms

You will likely not notice any drivability problems, although there may besymptoms such as a rough/hard idle when cold.

DTC p0431 - possible causes

A code P0431 may mean that one or more of the following has happened:The catalytic converter is no longer functioning properlyAn oxygen sensor is not reading (functioning) properlyThere is an exhaust leak

How to fix OBD-II diagnostic trouble code p0431

Inspect for exhaust leaks. Next step is to measure the voltage at the oxygensensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensorwhile you're at it. One thing to note is that many vehicle manufacturers offer a longer warrantyon emissions-related parts. So if you have a newer car but it's out of it'sbumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

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