Ford Fiesta ST (2013–2017)
1.6L EcoBoost – common issues, typical fault codes and how this platform behaves when things go wrong.
At a Glance
- Engine: 1.6L turbocharged EcoBoost (petrol).
- Years covered: roughly 2013–2017 (UK/EU spec Mk7.5).
- Known for: strong tuning potential, but sensitive to boost leaks and maintenance.
Common Issues on This Platform
- Misfires on cold start – typically coil packs, spark plugs or occasionally injectors on tuned cars.
- Boost leaks from intercooler pipe joints, cracked plastic pipes or loose clamps.
- Wastegate / boost control issues leading to underboost or overboost codes.
- Carbon build‑up on intake valves over higher mileage (direct‑injection behaviour).
- Clutch and gearbox wear on hard‑driven cars.
Typical OBD2 Codes on This Car
These examples link to general explanations. Use them together with the Fiesta‑specific notes here and the AI tools.
- P0300 – Random/Multiple Cylinder Misfire
- P0299 – Turbo/Supercharger Underboost (generic)
- P0299 on Fiesta ST – platform‑specific guide
- P0171 – System Too Lean (Bank 1)
- P0420 – Catalyst Efficiency Below Threshold
Extra Ford EcoBoost Codes Worth Knowing
These are additional high‑value codes that tend to show up on Ford EcoBoost platforms when something isn't quite right.
- P0171 on Ford EcoBoost – Lean running and air leaks
- P0300 on Ford EcoBoost – Random misfire behaviour
- P0299 on Ford EcoBoost – Underboost and lost performance
- P0420 on Ford EcoBoost – Catalyst efficiency issues
How to Approach Diagnostics
- Scan the car and note all stored codes, not just the first one.
- Fix obvious maintenance issues first – spark plugs, coils, air leaks, service items.
- Use live data (fuel trims, boost pressure, O2 sensor activity) to confirm what the ECU is seeing.
- Use the AI OBD2 Code Explainer with Fiesta‑specific details for a prioritised test plan.