P02B9: Cylinder 8 - Injector Leaking

What it means

The control module detects that fuel flow from the cylinder 8 injector continues when it should be closed. It sets this code when the detected leakage exceeds its calibrated limit; the code alone does not identify whether the nozzle, seal, or another part is responsible.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The cylinder 8 injector should stop delivering fuel when the engine control module commands it closed. This code sets when the module detects fuel continuing to enter cylinder 8 beyond its calibrated leakage limit; it does not by itself distinguish a leaking nozzle from a seal or control problem.

Common causes

Most likely first.

1. Injector nozzle or internal valve leaking
2. Injector seat or seal leaking
3. Injector stuck open or control fault
4. Excess fuel pressure

Symptoms

• Check-engine light
• Rough idle or engine vibration
• Misfire or hesitation
• Fuel odor or increased fuel consumption

How to diagnose it

1. Record freeze-frame data and check cylinder 8 misfire, fuel-trim, and start-up behavior to identify when excess fuel is most apparent.
2. With the engine off, inspect around the cylinder 8 injector and its seat for signs of fuel leakage, following the vehicle’s safety procedures.
3. Check the cylinder 8 injector connector and wiring for damage or a control fault that could keep the injector energized.
4. Compare fuel pressure and pressure retention with the manufacturer's specification to check for excessive pressure or leakage.
5. Use the approved injector leak or balance test to determine whether cylinder 8’s injector continues to pass fuel when closed.
6. If leakage is confirmed, inspect the injector seat and seal as well as the injector before deciding which part to replace.

Common fixes

• Repair damaged cylinder 8 injector wiring or a faulty connector causing unintended injector control.
• Correct fuel pressure that is above the manufacturer's specification.
• Replace a leaking cylinder 8 injector seal or repair its seat if leakage is localized there.
• Replace the cylinder 8 injector if testing confirms its nozzle or internal valve leaks.

Can I keep driving?

Avoid driving if you smell fuel, see a leak, or the engine is misfiring; shut it off and arrange safe inspection because fuel can ignite and excess fuel can damage the catalytic converter. If there is no external leak and the engine runs normally, keep any trip short and gentle while arranging diagnosis.