Citroen C2 rich running issue

Hey, that sounds frustrating! I had a similar problem with my old Vauxhall Astra, although it was a petrol engine. I was getting terrible fuel economy and a really rough idle. Have you checked your catalytic converter or O2 sensor? A faulty O2 sensor can definitely mess with the air-fuel ratio and cause the engine to run rich. It might be worth a look before you assume it's the injectors.

Thanks for the tip! The catalytic converter seems fine, but I haven't checked the O2 sensor specifically. Is there a good way to test it without just replacing it and hoping for the best? And did your Astra also have the jerking under acceleration, or was it just rough idling?

Yeah, the Astra was jerking too, especially when trying to accelerate quickly. I tried cleaning the O2 sensor, but that didn't fix it for long. Honestly, diagnosing it properly without the right tools is a pain. I ended up taking it to a workshop. They confirmed it was the O2 sensor, but also said the rich mixture had potentially damaged the catalytic converter over time. It ended up costing me a small fortune. Best to get it checked out by a professional I'd say!

Thanks for sharing your experience! I took your advice and brought the C2 to a trusted workshop. Turns out, the diagnosis was spot on – a defective injector. They replaced it for 515€, and now it runs like a charm again. Appreciate the heads-up about the O2 sensor; I'll keep an eye on that as well.