Peugeot 107 Combustion Misfires

That sounds frustrating! I had something similar occur with my 107. Misfires, rough idle, poor throttle response...It turned out to be a faulty fuel injector. Have you checked those? Sometimes, they get clogged or just fail outright. A defective fuel injector can cause a lean fuel mixture, leading to combustion misfires. If you are getting misfires only on one cylinder that's a pretty good hint.

Thank you for your response. How did you determine it was the fuel injector? Did you perform any specific tests, or did you simply replace them?

I initially suspected the ignition coil as well, as this is usually the first port of call with misfires. However, after swapping the coil with one from another cylinder, the misfire remained on the same cylinder. I would advise you to get the injectors tested at a workshop. In my case, they identified the faulty injector causing the misfires, and the replacement resolved the problem.

I appreciate your assistance. I will take your advice and consult a workshop to get the fuel injectors inspected. They have diagnosed the injection valve/injector defective and replaced it. The overall repair cost was 515€.