Ford Ka Jerking Acceleration

Hey there! Sounds like you've got a few things going on at once. That jerking and loss of power, combined with the error codes and rough running, does point to a potential engine misfire. But the strong exhaust smell has me wondering about a potential vacuum leak. Has anyone checked your manifold pressure? A leak in the intake manifold after the airflow sensor can cause unmetered air to enter the engine. This makes the air/fuel mixture lean, leading to misfires and rough running. Definitely look at all the hoses and connections around the intake manifold.

Manifold pressure, eh? I'm not super savvy with this stuff, so could you tell me a bit more about how the manifold could cause these exact symptoms? I can check hoses, but where exactly should I be looking for scorching?

Okay, so the intake manifold is basically what distributes air to each of the cylinders in your engine. If you've got a leak – maybe some scorching like you mentioned – unmetered air gets in. This messes with the air-fuel ratio, because the engine computer is expecting a certain amount of air based on what the airflow sensor detected before the leak. The 'misfire' happens because a cylinder isn't getting the right mixture to burn properly, hence the jerking and rough running. The ECU also reduces engine power in order to protect the engine. The exhaust smells because the catalytic converter isn't working efficiently with the incorrect mixture. It's hard to pinpoint the exact spot without a smoke test, but I'd advise getting it checked by a workshop. I did a smoke test once in my garage and it was a mess.

Cheers! Took your advice and brought it to a shop. Turns out the intake manifold was indeed knackered – leaking like a sieve due to scorching! Cost me 1180€ to fix, but she's running sweet as a nut now. Appreciate the help!