Leaking or sticking fuel injector on cylinder 6 delivering too much fuel; Faulty injector wiring, connector or driver fault affecting cylinder 6; Fuel pressure too high, for example a faulty regulator or pressure control fault (depends on engine and fuel system type); Exhaust gas sensor or air-fuel ratio sensor fault giving a falsely lean reading; Mechanical problem in cylinder 6 such as low compression or a valve or intake fault that upsets the mixture reading; Contaminated fuel or a faulty evaporative purge valve adding extra fuel vapour.

P02AF

Cylinder 6 - Fuel Trim at Min Limit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
AF: FaultThe specific fault in that area

What it means

P02AF means the engine control unit has found that the individual fuel trim correction for cylinder 6 has reached its minimum limit, so it cannot take out any more fuel. The ECU saw that cylinder 6 was running richer than the others, or richer than expected, and had already pulled the fuel delivery for that cylinder as far as it is allowed to. This code applies to engines that can adjust fuel trim cylinder by cylinder, and the way it is calculated depends on the engine.

Symptoms

Engine management light on
Rough idle or a misfire-like shake
Smell of unburnt fuel from the exhaust
Higher than normal fuel consumption
Black smoke or sooty tailpipe
Hesitation or uneven running under load

Possible causes

Leaking or sticking fuel injector on cylinder 6 delivering too much fuellikely
Faulty injector wiring, connector or driver fault affecting cylinder 6possible
Fuel pressure too high, for example a faulty regulator or pressure control fault (depends on engine and fuel system type)possible
Exhaust gas sensor or air-fuel ratio sensor fault giving a falsely lean readingpossible
Mechanical problem in cylinder 6 such as low compression or a valve or intake fault that upsets the mixture readingrare
Contaminated fuel or a faulty evaporative purge valve adding extra fuel vapourrare

How to diagnose

Read all stored and pending codes and freeze frame data, noting engine temperature, load and speed when the code set.
Check for other fuel trim, misfire or sensor codes, as these often point to the root cause.
Inspect the injector wiring and connector for cylinder 6 for damage, corrosion, or poor pin tension.
Review live data for short and long term fuel trims, comparing cylinder 6 with the other cylinders if the data is available.
Check fuel pressure against the manufacturer specification, and look at the regulator or pressure control system as the model requires.
Test the cylinder 6 injector for correct resistance, operation and leak-down, and compare its spray pattern or balance with the other injectors.
Check the purge valve operation and look for fuel vapour or fuel contamination in the intake.
Carry out a compression or leak-down test on cylinder 6 if the injector and fuel supply check out.

How to fix

Replace or professionally clean and flow-test the cylinder 6 injector if it is leaking or delivering too much fuel.
Repair or replace damaged injector wiring or connectors.
Correct fuel pressure faults by repairing or replacing the faulty regulator or pressure control component.
Replace a faulty exhaust gas or air-fuel ratio sensor once testing confirms it is giving false readings.
Repair any mechanical fault found in cylinder 6, then clear the code and road test to confirm it does not return.

Can I keep driving?

Medium severity

The car can usually be driven short distances, but get it checked soon. A rich-running cylinder can wash oil from the bore, foul plugs and overload the catalytic converter, so avoid long journeys or heavy loads if it runs roughly.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.