P23FE — Bank 1 System B Air-Fuel Ratio Imbalance
The secondary fuel system B on bank 1 (e.g. port-injection rail in a dual-injection engine, or LPG/CNG rail in a bi-fuel system) does not maintain calibrated mixture - lambda response on bank 1 is biased by an offset on the B system.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Fuel system b b1
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Secondary fuel system has drifted
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.