Citroen C5 throttle valve issue

Hmm, higher fuel consumption and poor starting could be throttle-related, but it's not a slam dunk. Have you noticed any other symptoms? Rough idling, maybe? Any error codes popping up on the dash? Before jumping to the throttle valve, I'd be checking the basics. Air filter clean? Fuel filter okay? When was the last time you had a proper service?

Thanks for the quick reply! No rough idling, strangely enough, and no error codes. Filters should be okay; I had a service about 10,000 km ago, but who knows if they actually changed everything they said they did, right? So, if it's not the throttle valve itself, what else could cause those symptoms? Is there any way I could check the accelerator pedal module?

Okay, no error codes is interesting. It could still be the throttle position sensor playing up without throwing a code, but without proper diagnostic tools, it's tough to be sure. As for the accelerator pedal module, testing that requires specific equipment. Honestly, at this point, and given your mileage, I'd suggest a workshop visit. They can properly diagnose the throttle system and check for any other underlying issues. Save yourself the guesswork and potential for making things worse.

You're spot on. I took it to the shop. Turns out it was the throttle valve, just like I suspected! Defective accelerator pedal module, too. 205€ later, she's running like a dream again. Thanks for the advice!