Error code P1187 is displayed and the check engine light is on - what does this mean?
The DTC P1187 is a manufacturer-specific fault code that is recognized by the OBD/EOBD diagnostics and indicates a problem with the fuel system. This trouble code mainly concerns the fuel-air mixture and the mixture control. This fault code can have different meanings for different manufacturers, but usually refers to a mixture composition that is too lean.
What causes can this fault code have?
- Defective lambda sensor or O2 sensor
- Clogged or defective fuel filter
- Damaged fuel pump
- Leaks in the intake system
- Defective mass air flow sensor (MAF)
- Clogged fuel injectors
- Defective fuel pressure regulating valve
- Cracks or damage in vacuum lines
- Faulty engine control unit (ECU)
- Loose or corroded plug connections
What symptoms occur in parallel with fault code P1187?
- Engine performance: Noticeable loss of power and uneven engine running
- Fuel consumption: Increased consumption despite lean mixture composition
- Starting behavior: Difficulties with cold starts or longer starting times
- Idle problems: Irregular or excessive idling
- Exhaust behavior: Increased emission values during the emissions test
- Jerking: Vehicle jerks especially at low engine speeds
How can the problem with error code P1187 be rectified?
- Repairing EOBD error code P1187 requires a systematic approach to identify the exact cause.
- Check the lambda sensor and replace if defective, as it is essential for correct mixture control
- Replace fuel filter and test fuel system for continuity and correct pressure
- Clean or replace the mass air flow sensor if the measured values are out of specification
- Check the intake system for leaks and replace damaged hoses or seals
- Clean fuel injectors professionally or replace if heavily soiled
- Check vacuum lines for cracks and replace defective lines
- Check electrical connections and clean or replace corroded plugs
FAQ - Frequently asked questions about DTC P1187
Can I continue driving with error code P1187?
Short distances are possible, but code P1187 should be rectified promptly as it can lead to engine damage. A mixture that is too lean can cause overheating and expensive consequential damage.
How much does it cost to repair error code P1187?
Depending on the cause, the costs vary between €50 for a filter change and €800 for replacing the lambda sensors or fuel pump. A precise diagnosis is required for a cost estimate.
Is the trouble code P1187 the same for all manufacturers?
No, P1187 is a manufacturer-specific code and can have different meanings for different brands. A vehicle-specific diagnosis is therefore essential.
How long does it take to repair fault code P1187?
Depending on the cause, between 30 minutes for simple work and up to 4 hours for more complex repairs such as replacing the fuel pump. The diagnosis time is an additional 1-2 hours.
Can I repair DTC P1187 myself?
Simple work such as filter changes can be carried out by non-professionals, but most repairs require specialist knowledge and special tools. Professional diagnosis is recommended.
Will the fault code P1187 return after the repair?
If the root cause has been repaired correctly, the code should not return. If it returns, the actual cause may not have been rectified or there may be another defect.