P231E
Cylinder 11 Air-Fuel Ratio Imbalance Adjustment At Limit During Balance
What it means
The ECU continuously trims individual cylinders to equalise air-fuel ratio across the bank using ion-current or per-cylinder lambda feedback. For cylinder 11 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?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Fuel injector for cylinder 11 has drifted in flow rate
highOne of the most commonly reported causes for this code — check this first.
Reduced compression on cylinder 11
mediumA plausible cause — test and verify before replacing parts.
Related help
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P231E freeNo credit card required