Thalia Hissing Sound Fuel Consumption

Dude, that sounds familiar! I had something like that happen with my Thalia. Check your vacuum hoses, especially the one going to the intake. Mine was cracked, hissing like a punctured tire. It messed with the air/fuel mix, like trying to bake a cake with half the ingredients missing.

Thanks for the tip! Could you tell me roughly where that hose is located? And did you also get engine misfires, or just the hissing?

Yep, I had some rough idling too, which could be misfires. The hose was near the turbocharger, if your engine has one. Honestly, though, if you're not super comfortable poking around, a workshop visit might be a good idea. It shouldn't cost an arm and a leg - my repair was around 100€, including the part.

Appreciate the advice! I'll check the hose myself, but will take it to a workshop if needed. It was the intake hose, just like you said. Replaced it and all good now!