Code P2297 indicates that the Engine Control Module has detected an out-of-range voltage signal from the Bank 1 Sensor 1 (upstream) oxygen sensor specifically during deceleration. When the throttle is closed, fuel delivery is temporarily cut, and the exhaust should become extremely lean; if the sensor fails to report this lean condition, the code is triggered.
The upstream oxygen sensor degrades over time, becoming slow to respond or biased rich, failing to drop its voltage during deceleration fuel cut-off.
An exhaust leak before or near the Bank 1 Sensor 1 allows ambient oxygen into the exhaust stream, skewing the sensor's lean reading during deceleration.
Unmetered air entering the engine from a vacuum leak can alter the air-fuel mixture enough to prevent the expected lean condition during deceleration.
A fuel injector that is stuck open or leaking will continue to dump fuel into the cylinder during deceleration, causing a rich condition instead of the expected lean state.
Corroded, chafed, or loose wiring and connectors at the O2 sensor can cause erratic voltage readings that fall out of the expected parameters.
Though extremely rare, an internal PCM failure could misinterpret the O2 sensor signal or incorrectly command fuel during deceleration.
You can drive cautiously for short periods, but prolonged driving can cause catalytic converter damage from an improper air-fuel mixture and will result in poor fuel economy.
No, this code points to the upstream oxygen sensor or the engine's air-fuel mixture during deceleration, not the catalytic converter itself.
During deceleration, the PCM cuts fuel to save gas and reduce emissions, making the exhaust lean. The PCM uses the upstream O2 sensor to verify this lean state; if the sensor fails to read lean, the code triggers.
Almost never. Mechanics frequently warn against replacing the PCM for P2297. The code is overwhelmingly caused by a degraded upstream O2 sensor, an exhaust leak, or a fuel control issue, not a defective engine computer.