Severity: High
Black Smoke From Exhaust
Black smoke usually means the engine is running rich: too much fuel, not enough air, or incorrect sensor data.
Most likely causes
- Rich fuel trim
- Dirty MAF
- Leaking injector
- Clogged air filter
- Turbo/boost leak on diesel
First checks before replacing parts
- Check air filter and intake restriction
- Review fuel trims
- Inspect MAF/MAP readings
- Check injector balance
- Inspect boost hoses on turbo engines
Related systems
- Fuel trim
- Air intake
- Injectors
- Turbo/boost