Peugeot 406 high fuel consumption

Hello, I had similar issues with my old Opel Astra – different make, I know, but same symptoms. Turned out to be a defective accelerator pedal module causing the throttle to act up. Have you checked that?

Accelerator pedal module? I'm not too familiar with that. Where is it located, and is there any way to test it myself?

Yes, the accelerator pedal module. On my Opel, it was integrated with the pedal itself. Honestly, diagnosing it properly requires specific equipment. Given your symptoms and the mechanic's initial assessment, I'd advise taking it to a workshop for a thorough check. It cost me around 205€ to get mine fixed.

Thanks for the advice. I took it to a workshop, and you were right – it was the accelerator pedal module! They replaced it, and the car is running much better now. Fuel consumption is back to normal, and it starts perfectly. The repair cost was indeed 205€.