The engine computer has detected that the oxygen sensor located after the catalytic converter (Bank 1, Sensor 2) is reporting a constant rich condition. This means the sensor signal is stuck at a high voltage and is not fluctuating as it should during normal operation.
The sensor has suffered internal failure or contamination, causing it to report a constant high voltage.
Shorts or open circuits in the sensor wiring harness can cause the signal to be biased toward a rich reading.
Leaks in the exhaust manifold or piping near the sensor can introduce air or disrupt gas flow, skewing the reading.
A leaking fuel injector or excessive fuel pressure can create a genuine rich condition that the sensor is correctly reporting.
The engine control module is incorrectly interpreting the voltage signal from the sensor.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
Not necessarily. This code indicates a problem with the sensor signal itself, not the efficiency of the catalyst.
Usually not. Because Sensor 2 is primarily used to monitor the catalytic converter, it does not typically influence the short-term fuel trim.
No. It is very rare for this code to be caused by the PCM; it is almost always a failed sensor, wiring issue, or exhaust leak.