Sticking or partially open injector pintle due to carbon deposits or debris; Worn or damaged injector nozzle or seat allowing fuel to seep past; Faulty injector O-ring or seal causing external or internal leakage; Wiring harness or connector corrosion causing intermittent injector operation; Contaminated fuel or fuel system debris holding the injector open; Engine control module driver circuit fault holding the injector energized

DTC codes / P02xx · Fuel and air metering (injector circuits) / P02B5

P02B5Cylinder 7 - Injector Leaking

Q: What does code P02B5 mean?

Cylinder 7 - Injector Leaking. P02B5 indicates that the engine control module has detected a leaking condition in the fuel injector for cylinder 7, typically by monitoring fuel trim or pressure behavior that suggests excess fuel is entering that cylinder when it should not. The computer sets this code when the injector's electrical or flow characteristics fall outside the expected range for a sealed, non-leaking injector.

P02B5 indicates that the engine control module has detected a leaking condition in the fuel injector for cylinder 7, typically by monitoring fuel trim or pressure behavior that suggests excess fuel is entering that cylinder when it should not. The computer sets this code when the injector's electrical or flow characteristics fall outside the expected range for a sealed, non-leaking injector.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Often no symptoms besides the warning light, especially in early stages
Rough idle or misfire that may be more noticeable when the engine is cold
Strong fuel odor from the exhaust or engine bay
Black smoke or soot from the tailpipe due to rich running
Decreased fuel economy and elevated hydrocarbon emissions
Engine may stumble or hesitate under acceleration

Common causes, most likely first

Sticking or partially open injector pintle due to carbon deposits or debris
Worn or damaged injector nozzle or seat allowing fuel to seep past
Faulty injector O-ring or seal causing external or internal leakage
Wiring harness or connector corrosion causing intermittent injector operation
Contaminated fuel or fuel system debris holding the injector open
Engine control module driver circuit fault holding the injector energized

How to diagnose and fix it

Perform a visual inspection of the cylinder 7 injector and its connector for fuel stains or corrosion
Use a scan tool to check fuel trims and misfire counters for cylinder 7 to confirm the rich condition
Run a fuel injector balance test or cylinder contribution test to compare injector flow
Check injector resistance and compare with the manufacturer's specification
Remove the injector and inspect for external leaks or damaged seals, replacing seals as needed
Clean or replace the suspect injector with a known-good unit and retest
Clear the code and verify fuel trims return to normal after repair

Leaking injector versus rich fuel trim traps

A leaking injector can set this code without ever triggering a misfire code, so technicians who only look for misfires may overlook it.
Fuel trim readings that are negative on one bank but normal on the other often point to a single leaking injector rather than a system-wide rich condition.
A stuck-open injector can hydrolock a cylinder and cause catastrophic engine damage if ignored, so address the fault promptly.
Some aftermarket injectors have different flow rates that can mimic a leaking injector, so always compare part numbers and flow specifications.
A faulty oxygen sensor or fuel pressure regulator can create rich conditions that mislead diagnosis toward the injector; verify fuel pressure and sensor readings first.

Can I keep driving with P02B5?

You can drive cautiously to a repair shop if the engine runs smoothly and fuel smell is mild, but avoid hard acceleration and long trips. If you notice heavy fuel odor, black smoke, or misfiring, stop driving and have the vehicle towed to prevent catalytic converter damage or engine damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.