Fuel and air

P02AD — Cylinder 5 Fuel Injector Leaking

Severity: medium Drive with care, to a shop

What P02AD means

The engine control module has determined, from fuel trim data, cylinder behavior and fuel system readings, that the cylinder 5 injector is letting too much fuel through. Normally an injector opens only on a command pulse and seals tightly between injections. A leak makes that cylinder run too rich.

Symptoms

  • Check Engine light on
  • Rough idle or cylinder 5 misfire
  • Higher fuel consumption
  • Fuel smell near the engine or exhaust
  • Reduced power and hesitation
  • Long crank on hot restart
  • Fuel smell in the engine oil

Possible causes

  1. Leaking or internally worn cylinder 5 injector
  2. Worn or damaged injector seals or O-rings
  3. Injector circuit fault: open, short or poor connector contact
  4. Excessive fuel pressure from a regulator or pump problem
  5. Contaminated fuel or deposits keeping the injector from closing
  6. Air leak skewing the mixture and fuel trim readings

How to diagnose

  1. Read all codes and freeze frame data, and look for cylinder 5 misfire codes
  2. Review short-term and long-term fuel trims and mixture adaptation
  3. Inspect the injector, connector and wiring for fuel traces, corrosion or damage
  4. Check injector coil resistance and the ECM control signal
  5. Measure fuel pressure and how well it holds after shutdown
  6. Compare cylinder balance with a scan tool (injector balance or cylinder cutout)
  7. Check the oil for a fuel smell or a rising level
  8. Rule out intake and exhaust leaks

Common fixes

  • Replace the cylinder 5 fuel injector
  • Replace the injector seals and O-rings
  • Repair the injector wiring or connector
  • Fix the fuel pressure regulator or fuel pump fault
  • Change the engine oil if it is diluted with fuel

Questions and answers

What does P02AD mean?

It means the ECM detected fuel leaking through the cylinder 5 injector. The injector isn't sealing properly or is delivering extra fuel, so that cylinder runs rich.

Can I drive with code P02AD?

Only for a short trip to a shop. Extended driving risks diluted oil, misfires and a damaged catalytic converter.

Can I just clear the code?

Clearing it won't fix the cause, and the code will come back. Find and repair the injector or its circuit first.

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.