P219F: Cylinder 4 Air/Fuel Ratio Imbalance
3 vehicles · 1 makes
Most Reported On
P219F is an OBD-II diagnostic trouble code meaning “Cylinder 4 Air/Fuel Ratio Imbalance.” Generic SAE J2012 code. Sets when the PCM detects an air/fuel ratio imbalance in cylinder 4, running too rich or too lean versus the other cylinders on the bank. Detection uses the heated exhaust oxygen / air-fuel sensors along with crank and cam position inputs. A sustained rich condition can overheat the catalytic converter and a sustained lean condition can raise combustion temperatures, so it should be corrected. This code is most commonly reported on 2014-2025 Audi SQ5, 2009-2025 Audi Q5, and 2009-2021 Audi A4.
Common Causes
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P219F.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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FAQ
What does P219F mean?
P219F stands for "Cylinder 4 Air/Fuel Ratio Imbalance." Generic SAE J2012 code. Sets when the PCM detects an air/fuel ratio imbalance in cylinder 4, running too rich or too lean versus the other cylinders on the bank. Detection uses the heated exhaust oxygen / air-fuel sensors along with crank and cam position inputs. A sustained rich condition can overheat the catalytic converter and a sustained lean condition can raise combustion temperatures, so it should be corrected.
What are the most common causes of P219F?
The most common causes of P219F are: Worn or fouled spark plug on cylinder 4, Weak or failing ignition coil on cylinder 4, Clogged or leaking fuel injector on cylinder 4, Unmetered air leak (intake manifold gasket, vacuum hose, throttle body gasket), Faulty upstream oxygen / air-fuel ratio sensor, Contaminated MAF sensor, Fuel pressure/delivery problems. The specific cause varies by vehicle.
How much does it cost to fix P219F?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P219F?
Au7o has documented P219F across 3 vehicle models from 1 manufacturers: Audi.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.