Hi everyone,
I have a 2015 Fiesta ST and I’m dealing with an issue that no one has been able to properly diagnose.
After driving for a while (usually 15–20 minutes, once the engine is warm), a spanner light appears with “Engine Service Now”, and the car goes into limp mode. After restarting the car, everything goes back to normal.
The issue is very inconsistent — sometimes it happens every day for a week, then it disappears completely for 1–2 weeks.
What’s been done so far:
Cleaned the MAF sensor
Replaced the MAP sensor
Smoke test initially found a leak at the valve cover, which was replaced - After that, the car ran perfectly for about 3 months, but now the same problem is back
Now I did smoke test again - no leaks found
Fault code: P2279 (intake air system leak)
Additional thing I noticed:
On cold start, RPM sometimes fluctuates briefly while dropping, then stabilizes
Has anyone experienced something similar or knows what could cause this, especially with P2279 but no visible leak?
Any help would be really appreciated!
I have a 2015 Fiesta ST and I’m dealing with an issue that no one has been able to properly diagnose.
After driving for a while (usually 15–20 minutes, once the engine is warm), a spanner light appears with “Engine Service Now”, and the car goes into limp mode. After restarting the car, everything goes back to normal.
The issue is very inconsistent — sometimes it happens every day for a week, then it disappears completely for 1–2 weeks.
What’s been done so far:
Cleaned the MAF sensor
Replaced the MAP sensor
Smoke test initially found a leak at the valve cover, which was replaced - After that, the car ran perfectly for about 3 months, but now the same problem is back
Now I did smoke test again - no leaks found
Fault code: P2279 (intake air system leak)
Additional thing I noticed:
On cold start, RPM sometimes fluctuates briefly while dropping, then stabilizes
Has anyone experienced something similar or knows what could cause this, especially with P2279 but no visible leak?
Any help would be really appreciated!
