Bank 2 (cylinders 4-6) counterpart to P1128. The Porsche-specific long-term fuel-trim adaptation for bank 2 has reached its limit, normally because the engine is lean and cannot be enriched further. On the M96/M97 flat-six the two banks share the same intake, so P1130 nearly always appears alongside P1128 and points to a common unmetered-air source rather than a single-bank fault.
SYMPTOMS
- Check-engine light
- Rough or slightly high idle
- Hesitation when cold
- Minor economy loss
LIKELY CAUSES
- Failed air-oil separator (AOS)
- Intake/vacuum leak (boots, hoses, manifold O-rings)
- Loose oil filler cap or dipstick-tube leak
- Dirty or failing MAF
- Fuel delivery shortfall under load
DIAGNOSIS STEPS
- Read fuel trims - positive LTFT on both banks points to a shared vacuum leak
- Smoke-test the intake and replace the AOS if the diaphragm is torn
- Clean/test the MAF
- Check oil cap and tube seals
- Verify fuel pressure
- Clear and road-test
RELATED PARTS
- Air-oil separator (AOS)
- Intake boots / vacuum lines
- MAF sensor
- Oil filler cap