Fuel and air

P02B5 — Cylinder 7 Injector Leaking

Severity: medium Drive with care, to a shop

What P02B5 means

The engine control module detected that the cylinder 7 injector is leaking or not delivering fuel as commanded. An injector should stay sealed between pulses and open for a precisely timed interval when the module signals it. A leaking or sticking injector floods that cylinder and throws off the mixture and rail pressure.

Symptoms

  • Check Engine light on
  • Rough idle and engine vibration
  • Cylinder 7 misfire
  • Higher fuel consumption
  • Weak acceleration and power loss
  • Fuel smell from the exhaust and higher emissions
  • Hard starting when hot

Possible causes

  1. Leaking or mechanically failed cylinder 7 injector
  2. Open or shorted wiring, or a poor connector contact at the injector
  3. Dirty injector affecting sealing or spray pattern
  4. Faulty fuel pressure regulator or rail pressure sensor
  5. Intake air leak skewing the mixture
  6. ECM software fault or sensor misreporting (uncommon)

How to diagnose

  1. Scan all codes and freeze frame data, and look for related misfire codes
  2. Review fuel trims and compare cylinder balance data
  3. Inspect the cylinder 7 injector connector and harness for damage and corrosion
  4. Check injector resistance and the control signal from the ECM with a scope or noid light
  5. Measure fuel pressure and how well it holds after shutoff
  6. Bench test the injector for leakage and spray pattern
  7. Inspect the intake and vacuum hoses for air leaks
  8. Check the oil for a fuel smell or a rising level

Common fixes

  • Replace the cylinder 7 fuel injector
  • Repair the injector wiring or connector
  • Ultrasonically clean the injector if it is not worn
  • Replace the fuel pressure regulator or pressure sensor
  • Update or reflash the ECM if a software fault is confirmed

Questions and answers

Can I drive with a P02B5 code?

Only briefly and until it's repaired. A leaking injector can dilute the oil and damage the cylinder and catalytic converter, so don't delay.

What does P02B5 mean?

The ECM sees the cylinder 7 injector leaking or delivering fuel abnormally. The cause can be the injector itself, its wiring, or fuel pressure.

Will cleaning the injector fix it?

Sometimes, if the cause is deposits. If the injector is worn or physically leaking, it needs to be replaced.

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.