Engine light flashing and rough running in your Focus RS? We diagnosed a misfire across multiple cylinders in our Newtownabbey garage. Learn what caused it and how we fixed it.
When your engine light comes on and your car feels rough, hesitant, or low on power — it can be due to a misfire. That’s exactly what happened with a Ford Focus RS that recently arrived at our Newtownabbey garage.
The car was misfiring across multiple cylinders, and the check engine light had been flashing. Our team quickly diagnosed the issue and helped the driver avoid further damage.
A misfire means the air-fuel mixture in one or more cylinders isn't igniting correctly. Common causes include:
Faulty ignition coils or spark plugs
Failing fuel injectors
Vacuum leaks
Timing issues
ECU or wiring faults
In turbocharged cars like the Focus RS, worn plugs or coil packs are especially common causes of misfiring and rough idling.
At 1Stop Motor Shop, we used advanced diagnostic tools to scan for fault codes. The scan showed multiple cylinder misfires — not isolated to one plug or coil.
Our step-by-step process included:
Checking ignition components
Inspecting wiring and coil packs
Verifying fuel pressure and injector operation
Reviewing data logs for boost and timing irregularities
In this case, the likely culprits were weak coil packs, all were replaced on-site with quality parts.
Ignoring a misfire can lead to:
Catalytic converter damage
Excess fuel in the exhaust
Poor fuel economy
Loss of power and rough driving
Long-term engine damage
If your engine light is flashing or you feel a loss of performance, book in at our Newtownabbey garage near Belfast for fast diagnostics and expert repairs.
We specialise in turbocharged performance vehicles, including the Ford Focus RS, and offer:
Engine diagnostics and code reading
Spark plug and coil pack replacements
Full misfire fault tracing
Honest, no-jargon repairs for drivers across Belfast
Trusted by drivers across Belfast - how to contact us:
- Call/WhatsApp (phone and text): 07951 728365
- DM our socials (Facebook & Instagram)
- Email: OneStopMotorShop@hotmail.com
- Contact us via our website
