Porsche-specific: Bank 1 adaptive fuel trim reached its maximum limit leaning out — running too rich. Commonly pairs with P1128 when the MAF is faulty. Both P1128 and P1130 are Bank 1, not separate banks.
SYMPTOMS
- Check-engine light
- Rich running
- Possible fuel smell
- Fouled plugs
LIKELY CAUSES
- Faulty or dirty MAF
- Leaking injector
- High fuel pressure
- Contaminated O2 sensor
DIAGNOSIS STEPS
- Inspect/clean the MAF
- Check injectors for leakage
- Verify fuel pressure
- Inspect O2 sensors
RELATED PARTS
- MAF sensor
- Fuel injectors
- O2 sensors