Twingo Rich Running Condition

That sounds familiar. I had a similar issue with my 2015 Opel Astra diesel. Reduced power, check engine light, rough running, poor fuel economy, and jerking all point towards a rich mixture. A defective injector is a prime suspect. Think of it like a leaky faucet, constantly dripping fuel into the engine. Have you checked the spark plugs or the intake manifold for signs of excessive fuel?

Thanks. You mentioned checking the spark plugs and intake manifold. What specific signs should I look for to confirm the rich running condition?

When examining the spark plugs, look for a dark, sooty, or oily residue. That indicates incomplete combustion due to excess fuel. For the intake manifold, check for fuel pooling or excessive carbon buildup. It should appear relatively clean and dry. Given the symptoms and the potential for damage to the catalytic converter from a persistently rich mixture, I'd recommend a workshop diagnostic check. The cost should be around 515€.

I appreciate the explanation and recommendation. I took the Twingo to a workshop. The diagnosis confirmed a faulty injector, which was replaced. The engine now runs smoothly, and fuel consumption is back to normal. Thanks for your assistance.