Peugeot 108 Combustion Misfire

Those symptoms – rough running, check engine light, jerking under acceleration, and reduced power – strongly indicate a persistent combustion misfire. Given that you've inspected the ignition components, the next area should be the fuel delivery system. Have you considered examining the function of the fuel injectors? A malfunctioning injector can cause lean combustion, resulting in the issues you are experiencing.

Fuel injectors, huh? I haven't really messed with those before. Is there a way to check them without special tools? Is it something I can do myself, or am I better off taking it to a shop?

While some rudimentary tests can be performed, such as listening for injector 'tick' with a stethoscope or using a multimeter to check coil resistance, these offer limited diagnostic insight. Your safety is paramount; fuel systems operate under significant pressure. Given the potential for fuel leaks and the precision required to properly diagnose injector performance, it is advisable to consult a qualified technician. It's like trying to perform open-heart surgery with a butter knife – possible, but strongly discouraged!

Thanks for the advice! Took it to the shop as you suggested. Turns out it was a defective fuel injector causing all the mayhem. New injector fitted, cost me 515€, but she's running like a dream now!