Code P2197 indicates that the engine computer has detected the upstream oxygen sensor on Bank 2 is reporting a constant lean condition (too much oxygen in the exhaust). This means the sensor signal is biased or stuck and not responding to normal fuel mixture adjustments.
Unmetered air entering the engine or an exhaust leak upstream of the sensor can cause a genuine lean condition that the sensor is accurately reporting.
The sensor itself may be degraded, contaminated, or internally shorted, causing it to send a false lean signal to the computer.
Low fuel pressure, a restricted fuel injector on Bank 2, or a failing fuel pump can create an actual lean mixture.
Corroded, chafed, or disconnected wiring to the Bank 2 Sensor 1 can disrupt the voltage signal and cause a false reading.
A rare internal failure in the computer's sensor input circuit can misinterpret the signal, though this is highly uncommon.
Not necessarily. While the sensor may have failed, it is equally likely that the sensor is correctly reporting an actual lean condition caused by a vacuum leak or low fuel pressure.
Short-distance driving is generally safe, but prolonged driving with a lean condition can cause engine overheating and permanent damage to the catalytic converter.
If the underlying issue is resolved, the engine computer may eventually clear the code after several drive cycles, but manually clearing it with a scan tool is standard practice after repairs.
Almost never. Mechanics or parts sellers sometimes blame the PCM for sensor codes, but control module failure is extremely rare. The fault almost always lies with the sensor, the wiring, or an actual engine lean condition.