Cylinder 2 injector sticking open or leaking at the tip; Carbon or debris holding the injector nozzle or seat from sealing; Worn or damaged injector seals or internal valve; Fuel pressure regulation fault or excessive rail pressure causing the injector to leak; Wiring or connector fault giving incorrect injector drive to cylinder 2; Contaminated or poor quality fuel affecting injector operation; Faulty ECU injector driver.

P02A1

Cylinder 2 - Injector Leaking.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
A1: FaultThe specific fault in that area

What it means

P02A1 means the engine control unit has detected that the fuel injector on cylinder 2 is leaking, so fuel is reaching the cylinder when it should not be. The ECU usually infers this from fuel rail pressure decay, fuel trim or combustion/misfire behaviour that does not match the commanded injection. The exact detection method depends on the engine and fuel system, whether petrol direct injection or diesel.

Symptoms

Engine warning light on
Hard starting or long cranking, especially when hot
Rough idle or misfire on cylinder 2
Smell of fuel from the exhaust or oil
Rising oil level or oil smelling of fuel
Poor fuel economy

Possible causes

Cylinder 2 injector sticking open or leaking at the tiplikely
Carbon or debris holding the injector nozzle or seat from sealinglikely
Worn or damaged injector seals or internal valvepossible
Fuel pressure regulation fault or excessive rail pressure causing the injector to leakpossible
Wiring or connector fault giving incorrect injector drive to cylinder 2possible
Contaminated or poor quality fuel affecting injector operationrare
Faulty ECU injector driverrare

How to diagnose

Read all stored codes and freeze frame data, noting engine temperature, load and fuel pressure when the fault set, and check for misfire or fuel trim codes
Inspect the cylinder 2 injector wiring and connector for damage, corrosion, looseness or heat damage
Check the engine oil level and smell for fuel dilution
Review live data for cylinder 2 misfire counts, fuel trims and fuel rail pressure behaviour after shutdown
Carry out a fuel pressure leak-down test following the manufacturer's procedure for that engine
Check the injector electrical resistance and drive signal against the specification for the model
Perform an injector balance or leak-off test where the engine design allows
Inspect the spark plug for cylinder 2 for signs of being wet or fouled with fuel, where applicable

How to fix

Replace the leaking cylinder 2 injector, along with its seals and any washers specified for the engine
Clean or replace the injector if carbon or debris is preventing it sealing, following the manufacturer's guidance
Repair or replace damaged wiring or connectors to the injector
Correct any fuel pressure regulation fault found, such as a faulty pressure regulator or pressure control valve
Change contaminated engine oil and filter if fuel dilution is confirmed, and drain and replace contaminated fuel if found

Can I keep driving?

High severity

Avoid driving until it is checked, as a leaking injector can wash the cylinder wall, dilute the engine oil and damage the engine. If it must be moved, keep it to a short, gentle journey to a workshop.

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