Fuel and air

P02B1 — Cylinder 6 Injector Leaking

Severity: medium Drive with care, to a shop

What P02B1 means

The engine control module has detected that the cylinder 6 fuel injector is letting fuel through when it should be closed. It usually shows up in fuel trims, in rail pressure that bleeds off after shutdown, or in uneven cylinder performance. The extra fuel enriches the mixture in that cylinder and can dilute the engine oil.

Symptoms

  • Check Engine light on
  • Rough or uneven idle
  • Misfire, especially at low RPM
  • Worse fuel economy
  • Fuel smell or black exhaust smoke
  • Loss of power or hesitation
  • Long cranking or hard hot restart

Possible causes

  1. Leaking or faulty cylinder 6 fuel injector
  2. Worn or damaged injector seals, O-rings, or seat
  3. Contamination keeping the injector from sealing
  4. Excessive fuel pressure from a bad regulator or pump
  5. Open, short, or poor contact in the injector wiring or connector
  6. Injector driver fault in the ECM (rare)

How to diagnose

  1. Scan all codes and freeze-frame data and look for misfire codes
  2. Review short- and long-term fuel trims and cylinder balance
  3. Test fuel pressure while running and how well it holds after shutdown
  4. Inspect the cylinder 6 injector connector and harness, then check coil resistance and the drive signal
  5. Pull the cylinder 6 spark plug and look for black, wet, or fouled deposits
  6. Check the oil for a fuel smell or a rising level
  7. Swap injectors between cylinders to see if the fault follows the injector
  8. Bench test the injector for leakage and spray pattern

Common fixes

  • Replace the leaking cylinder 6 injector
  • Replace injector O-rings and filter screens
  • Repair the injector wiring or connector
  • Fix the cause of high fuel pressure, such as the regulator or fuel pump
  • Change the oil if it is fuel-diluted and reset fuel trim adaptations

Questions and answers

Can I drive with P02B1?

Only briefly and under light load. A leaking injector dilutes the oil and can damage the catalytic converter and cylinder, so repair it soon.

What should I do after replacing the injector?

Clear the code and reset the fuel trim adaptations. If the car ran with a leak for a while, change the oil and filter since fuel may have diluted 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.