Espace intake manifold flap control

I had similar symptoms with my Espace, although I don't know the year off-hand. Was the engine light illuminated? Did you notice any unusual noises? Also, can you confirm if the reduced power is consistent or intermittent? Understanding the specifics of your experience can help narrow down the potential causes and determine the most appropriate course of action.

Cheers for the reply! Yeah, the engine light is definitely on, glaring at me. The hissing is constant when accelerating, and the power loss is pretty consistent, especially noticeable when trying to overtake. Did yours do the same?

Affirmative, the hissing sound during acceleration and the consistent power reduction are highly indicative of a malfunctioning intake manifold flap control. Based on your description and my past experience, I strongly suggest you take your Espace to a qualified workshop for a thorough diagnosis and repair. Ignoring this issue could lead to more severe engine damage.

Thanks a bunch for confirming my suspicions! Took it to the shop, and you nailed it. Intake manifold flap control switch was indeed the culprit. 465€ lighter now, but she's running sweet as a nut again. Appreciate the help!