GLK Engine Issues Manifold Pressure Sensor Suspected

I had something similar happen with my GLK. Reduced engine power and the check engine light were the first signs. I think the manifold sensor is responsible for measuring the air pressure in the intake manifold. If it goes bad, the engine's computer gets wrong information, which throws everything off. Did you check for any obvious signs of leaks, like hissing noises?

Thanks for the quick reply! I did a quick visual inspection, but didn't hear any hissing. Where exactly should I be looking for these vacuum leaks? I'm guessing around the intake manifold itself? Is there a specific area that's more prone to leaks on these engines? I'm trying to avoid taking it to a shop if it's something I can handle myself.

Honestly, I'm not entirely sure where the most common leak points are on the GLK. My issue ended up being the manifold sensor itself, even though I suspected a vacuum leak at first too. It's probably best to have a mechanic take a look. They have smoke machines and other tools to find leaks you might miss. I ended up just biting the bullet and taking it to a workshop. Saved me a lot of time and headache in the long run.

Appreciate the advice! I think you're right, it's time to let the pros handle it. Turns out it WAS the manifold pressure sensor, just like the OBD reader said. New sensor and labor cost me 235€. Runs like a champ again! Thanks for confirming my suspicions and saving me from chasing ghosts.