The control module detected a fault associated with the Cylinder 8 Air - Fuel Ratio Imbalance circuit or function; the stored code identifies the affected component rather than a single failure mode.
TuningBot DTC Database · v4.37.14
P21A3 Cylinder 8 Air - Fuel Ratio Imbalance
Generic (OBD-II) interpretation in the TuningBot DTC database.
What P21A3 means
Related and nearby codes
How to read P21A3
Powertrain: engine, transmission and driveline systems.
Generic SAE-standard code: same meaning on every make.
Specific fault index within the subsystem.
Frequently asked questions about P21A3
What does P21A3 mean?
Cylinder 8 Air - Fuel Ratio Imbalance. The control module detected a fault associated with the Cylinder 8 Air - Fuel Ratio Imbalance circuit or function; the stored code identifies the affected component rather than a single failure mode.
Is P21A3 generic or manufacturer-specific?
P21A3 is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.
Can TuningBot remove P21A3 at file level?
If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry and, where the ECU needs it, corrects the checksum too. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.
Other file services
Understand the system behind this code: Diagnostic Strategy and DTC Logic
