P200E
Catalyst System Over Temperature (Bank 1)
A temperature sensor in the exhaust catalyst on bank 1 reports a value above the safe operating limit. Sustained over-temperature can sinter the precious-metal washcoat and destroy conversion efficiency.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Common causes
Ordered by how often each turns out to be the cause.
- Persistent misfire dumps unburned fuel into the catCommon
- Sustained rich mixture from leaking injector or fuel pressure regulatorPossible
- Catalyst temperature sensor drifts highLess likely
Parts involved
- Catalytic Converter
- Exhaust Temperature Sensor
P200E is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.