Kangoo air intake leak

Oh man, that sounds familiar! I had similar symptoms on my Kangoo. Check engine light, the hissing noise... It was driving me nuts. I think you should check for cracks in the intake hose, which runs from the air filter box to the engine. It’s a common point of failure. It’s located near the turbocharger. Sometimes it is difficult to spot with the naked eye so I recommend you to touch it to check. Good luck!

Thanks for the tip! When you say intake hose, are you referring to the corrugated flexible one? And was the hissing constant, or only under load? I'm trying to narrow it down before I commit to replacing parts.

Yes, exactly, the corrugated flexible one. It's prone to cracking, especially with age and heat. In my case, the hissing was definitely more pronounced when the engine was under load, especially when accelerating. The check engine was always on. If the hose is leaking, replacing it is a good idea, but I would recommend you to go to the workshop and have someone take a look at it before.

Thanks so much for the clarification! It sounds exactly like what I'm experiencing. I'll take a closer look at that hose, and if it’s cracked, I will replace it. I went to the workshop today and they confirmed that the intake hose was leaking and it needed to be replaced. The whole repair cost me 100€. You were right on the money. Appreciate the help!