Mark X rough engine running

I see. I had a similar issue with my Mark X some time ago. Does the engine run unevenly at idle, too? And can you hear any unusual hissing or puffing sounds from under the car, especially near the exhaust?

Yes, it is uneven at idle, too! And I think I might have heard something like that under the car recently. What was the problem with yours?

In my case, it turned out to be a small leak in the exhaust system before the catalytic converter. This can cause the engine to run lean, triggering the check engine light and causing rough running. Considering your symptoms, I'd advise a thorough inspection of the exhaust system. The repair itself wasn't too expensive. However, without proper equipment, the location of the leak can be difficult to find. Best visit your local workshop.

Thanks a lot for your help! I went to a mechanic. Turns out, it was indeed a leak in the exhaust system! Cost me 265€ to fix. Runs great now!