OBD-II code · Powertrain (generic, extended)
P230A Cylinder 1 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
The ECU continuously trims individual cylinders to equalise air-fuel ratio across the bank using ion-current or per-cylinder lambda feedback. For cylinder 1 the per-cylinder fuel correction has hit its software-side maximum or minimum without restoring balance, indicating the underlying mechanical or fuelling deviation is too large to compensate.
Is it safe to drive with P230A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFuel injector for cylinder 1 has drifted in flow rate
- PossibleLocal intake or vacuum leak at cylinder 1
- PossibleReduced compression on cylinder 1 (valves, rings)
- Less likelyPartial misfire from ignition or fuel-side defect
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Injector Cyl 1, Intake Manifold, Cylinder Compression, Per Cylinder Lambda Strategy
Related codes
- P230BCylinder 2 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P230CCylinder 3 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P230DCylinder 4 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P230ECylinder 5 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P230FCylinder 6 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231ACylinder 7 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231BCylinder 8 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231CCylinder 9 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231DCylinder 10 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231ECylinder 11 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P231FCylinder 12 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
- P2307Ignition Coil C Primary Control Circuit High
- P2308Ignition Coil C Secondary Circuit
- P2309Ignition Coil D Primary Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.