CrosslandX Reduced Engine Power

Sounds familiar. I had similar issues with my old Peugeot 308. It turned out to be a defective main relay causing the ECU to act up. Have you checked that?

No, I haven't checked the main relay. Where is that located and how do I test it?

On my Peugeot, it was in the engine compartment fuse box. Honestly, testing it properly requires some electrical knowledge. Given your symptoms and the stored error, I'd recommend getting it checked at a workshop. Could save you a lot of headache.

Thanks for the advice. Took it to the workshop, and you were right, it was the main relay. Repair cost me 120€. All sorted now.