Fuel and air

P02A5 — Cylinder 3 Fuel Injector Leaking

Severity: medium Drive with care, to a shop

What P02A5 means

The engine control module has found that the cylinder 3 injector is letting fuel through when it should be closed, or is delivering fuel abnormally. Normally an injector opens for a precisely timed pulse and then seals tightly. A leak puts extra fuel into the cylinder, enriches the mixture and disturbs combustion.

Symptoms

  • Check Engine light on
  • Rough idle or engine shake
  • Misfire, often on cylinder 3
  • Reduced power and sluggish acceleration
  • Higher fuel consumption
  • Fuel smell from the exhaust or engine bay
  • Hard starting when the engine is hot

Possible causes

  1. Worn or sticking cylinder 3 injector that drips or leaks
  2. Failed or aged injector O-rings or seals
  3. Injector circuit problem: open circuit, corroded terminals or damaged wiring
  4. Fuel pressure too high, for example from a faulty regulator
  5. Faulty oxygen sensors skewing the mixture readings
  6. Intake air leak affecting fuel trims
  7. ECM software fault or internal failure (rare)

How to diagnose

  1. Scan all codes and freeze-frame data and look for cylinder 3 misfire codes
  2. Review short- and long-term fuel trims at idle and under load
  3. Inspect the cylinder 3 injector, connector and wiring for damage or fuel residue
  4. Measure fuel pressure and check how well it holds after shutoff
  5. Test injector coil resistance and the ECM control signal
  6. Compare cylinders with a scan tool: injector cut-out or balance test
  7. Pull the cylinder 3 spark plug; black soot or fuel wetness points to a rich condition
  8. Check for intake leaks and verify oxygen sensor operation

Common fixes

  • Replace the cylinder 3 injector, or have it cleaned and tested on a bench
  • Replace the injector O-rings and filter screens
  • Repair the injector wiring or connector
  • Replace the fuel pressure regulator if pressure is too high
  • Change the engine oil if it is diluted with fuel
  • Update ECM software or repair the module if nothing else is found

Questions and answers

What does P02A5 mean?

It means the ECM suspects the cylinder 3 fuel injector is leaking or delivering fuel incorrectly. It is often accompanied by misfires and a rough-running engine.

Can I drive with code P02A5?

Only briefly and to a repair shop. Excess fuel can dilute the oil and damage the catalytic converter, and heavy misfires can harm the engine.

Will replacing the injector fix it?

Often, but first check the wiring, fuel pressure and oil condition. If the cause is electrical or high fuel pressure, a new injector won't solve it.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.