OBD-II code · Powertrain (generic, extended)
P219A Bank 1 Air-Fuel Ratio Imbalance
The fuel-trim values across cylinders on bank 1 differ enough that the bank-average air-fuel ratio is biased — a single cylinder is significantly leaner or richer than the rest. Detected by short-term-fuel-trim variance or by the wide-band O2 sensor harmonic monitor.
Is it safe to drive with P219A?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyOne injector clogged or leaking
- PossibleVacuum leak at one intake runner
- Less likelyLow compression on one cylinder
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Injector, Oxygen Sensor, Intake Manifold
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.