Diagnostic article Generic OBD-II
P2297: oxygen concentration drift during stable deceleration
P2297 compares measured and estimated oxygen concentration during a qualified fuel-cut deceleration.
Read before applying this article
Documented application
2025 GM 25OBDG04B diagnostic parameter file; the cited monitor is documented, but individual vehicle, engine and calibration applicability has not been established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
The documented P2297 monitor checks whether the oxygen value associated with NOx sensor 1 drifts away from an estimated oxygen concentration during overrun. It is a plausibility comparison, rather than a direct declaration that an ordinary oxygen-sensor wire is open.
Why deceleration matters
The controller needs a stable reference. The difference between measured and estimated oxygen fails above 4.00 percentage points or below −3.25 percentage points. The source specifies 121 failures out of 240 samples on a 25 ms task and Type B, two-trip reporting.
The continuation page requires a stable fuel-cut condition for more than 3.5 seconds, engine speed between 600 and 3,000 rpm, EGR position below 60%, and a qualifying air-mass range. Estimated oxygen must itself remain stable. Exhaust-brake activity and several air-system or NOx-sensor faults can prevent a valid comparison.
Reading the result usefully
A sensor reading captured during acceleration is not evidence that this deceleration monitor passed or failed. Compare the two oxygen values only when the fuel-cut and stability criteria are met. Equally, failure of the enabling air-mass or pressure information can leave the monitor incomplete without proving the sensing element is defective. Verification should establish that the deceleration test actually ran and produced an acceptable comparison; clearing the code by itself provides neither observation.
Source and application limits
This explanation covers the cited 2025 GM monitor. Confirm the vehicle and calibration in its service information before applying these limits; inclusion in this file does not establish model compatibility. GM diagnostic parameters, PDF page 1423. GM diagnostic parameters, PDF page 1424.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
O2 Sensor Out of Range During Deceleration Bank 1 Sensor 1
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT