Seat Arona Uneven Engine Running Issue

Uneven running and jerking sounds like fun times NOT! Check engine light combined with those symptoms and error codes screams vacuum leak to me. A leak after the oxygen sensor but before the catalytic converter could definitely cause the engine to run lean and jerk during acceleration. The ECU is probably trying to compensate by adjusting the fuel mixture, hence the light. Have you checked for hissing sounds near the exhaust manifold or any obvious cracks or holes in the exhaust pipes? Although the fuel pump, timing belt, fuel injectors and spark plugs could also be a cause, the leak is way more likely.

Interesting, I hadn't considered an exhaust leak. When you say vacuum leak, do you mean anywhere from the engine to the exhaust, or specifically around the intake manifold area? I was leaning towards a fuel delivery issue but the exhaust is definitely easier to check first.

OK, to clarify, by vacuum leak, technically I'm referring to any unmetered air entering the system after the air flow sensor (or MAF sensor). However, in your case, given you suspect the exhaust and are getting jerking and a check engine light, a leak in the exhaust system is far more probable than an intake vacuum leak. A small exhaust leak, especially before any catalytic converters will absolutely mess with your oxygen sensor readings and cause havoc. I'd get a smoke test done on the exhaust system, it's the easiest way to pinpoint a leak. Seriously, save yourself a headache and rule that out first. If that doesn't solve it, then you can start digging deeper into the fuel system. If the smoke test doesn't find anything, bring it to the workshop.

Confirmed exhaust leak. Had it smoke tested and a small crack was found near the catalytic converter. Welding sorted it, total cost 265€. Thanks for pointing me in the right direction.