P219ABank 1 Air-Fuel Ratio Imbalance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P219A means the ECM sees mixture differences between the cylinders of bank 1 that are large enough to raise emissions, even if the bank average is fine. CARB phased this monitor in from 25 % of 2011 to all 2014 model-year petrol vehicles (13 CCR 1968.2 (e)(6.2.1)(C)). GM measures how much the upstream sensor signal varies per firing event, normalises the result against a map of a healthy engine and flags a ratio above 1.05 (one 2016 engine, 1100 to 3500 rpm, Type A, one trip). Mitsubishi counts rich and lean peaks at 1750 to 3250 rpm and 40 to 70 % volumetric efficiency. On inline engines bank 1 is the whole engine. Toyota traced P219A on 2012 to 2014 Corolla 2ZR engines to compression escaping into the exhaust; from 2014 the Corolla adds the cylinder codes P219C to P219F.
- What you may notice
- Check engine light on
- Often no noticeable symptom
- Slight rough running or misfire codes when one cylinder is far off
- Likely causes
- LikelyOne injector clogged, leaking or out of flow tolerance
- PossibleCompression loss through an intake or exhaust valve
- PossibleAir leak at one intake runner or gasket
- RareECM logic or sensor signal issue covered by software or wiring bulletins
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.