Seat Arosa running rich

Running rich, eh? I had something similar with my Seat (not sure what year though), also a gasoline engine. Check engine light, rough running, the works. Did you check the oxygen sensor? Is it giving correct values? Also, how old is your air filter?

Oxygen sensor, interesting. I thought about the fuel injectors first. Where exactly did you see issues with the oxygen sensor readings? And were your symptoms identical, like the jerking when accelerating?

Symptoms sound very similar. I didn't personally check the oxygen sensor, but the mechanic pointed out that it was giving weird readings because of the incorrect air-fuel ratio. Replacing the injectors fixed it, but he mentioned the faulty readings were a consequence of the rich running, not the cause. Probably best to get it checked out by a professional.

I've got it sorted. Turns out it was indeed the fuel injectors, just like we suspected. Had them replaced, and the air-fuel ratio is back to normal. Cost me 515€, but the Arosa is running smoothly again. Thanks for your input. Appreciate it.