Troubleshooting the Engine of a Ford Fiesta

I have a 2015 Ford Fiesta with a 1.6L engine that is making a strange noise. It starts fine but after a few minutes of driving, the engine starts to rattle and lose power. I've checked the oil and it's at the correct level. What could be causing this issue?

It sounds like you may be experiencing an issue with your fuel injectors. They could be clogged or malfunctioning, causing your engine to run lean. I recommend taking your car to a certified mechanic to have them inspected and possibly replaced.

Another possibility could be a problem with your spark plugs. If they are worn out or not firing correctly, it can cause a loss of power and strange noises. I suggest having them checked and replaced if necessary.

Have you checked your air filter? If it's dirty or clogged, it can restrict airflow to the engine and cause performance issues. Try replacing it and see if that improves your engine's performance.