Fuel and air

P02A1 — Cylinder 2 Fuel Injector Leaking

Severity: medium Drive with care, to a shop

What P02A1 means

P02A1 means the engine control module suspects the cylinder 2 injector is leaking, or is delivering fuel differently than commanded. The PCM judges this from oxygen sensor feedback, fuel trims and crankshaft speed variation. Extra fuel enriches that cylinder and upsets the air-fuel balance, so the engine runs unevenly.

Symptoms

  • Check Engine light on
  • Rough idle or engine vibration
  • Reduced power and sluggish acceleration
  • Higher fuel consumption
  • Misfires, possibly with misfire codes
  • Fuel smell from the exhaust or in the oil
  • Hard starting when hot

Possible causes

  1. Leaking or sticking cylinder 2 fuel injector
  2. Damaged injector connector or wiring
  3. Fuel pressure too high or unstable, or a faulty pressure regulator
  4. Faulty oxygen sensors skewing fuel trim
  5. Intake air leak shifting the mixture
  6. PCM software or module fault (rare)

How to diagnose

  1. Scan all codes and freeze frame data, and look for misfire codes
  2. Review short-term and long-term fuel trims and mixture adaptation
  3. Inspect the cylinder 2 injector connector and wiring, checking pins and ground
  4. Test fuel pressure and how well it holds after shutdown
  5. Compare cylinder balance or misfire counts, and swap the injector with a neighbor to see whether the problem follows it
  6. Measure injector resistance and check the drive signal with a scope
  7. Check the intake and exhaust for air leaks
  8. Inspect the cylinder 2 spark plug and check the oil level and smell

Common fixes

  • Replace the leaking cylinder 2 injector, and test or clean the others if needed
  • Repair or replace damaged wiring or the connector
  • Replace the fuel pressure regulator if pressure is wrong
  • Fix air leaks and replace a faulty oxygen sensor
  • Update PCM software or diagnose the module if all else is ruled out

Questions and answers

What does P02A1 mean?

The PCM found that the cylinder 2 injector is leaking or delivering fuel incorrectly. That makes the cylinder run richer and the engine run roughly.

Can I drive with P02A1?

Only a short distance, gently, to reach a shop. Extended driving can dilute the oil, damage the catalytic converter and increase cylinder wear.

How do I tell an injector fault from a wiring problem?

Check the connector and injector resistance, then swap the injector with a neighboring cylinder. If the code or misfire moves, the injector is bad. If not, look at wiring, fuel pressure or the PCM.

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.