Ranger diesel engine sluggish

Sounds familiar. I had similar symptoms on my Ranger. Reduced power and the engine light were the first signs. Have you checked for any vacuum leaks? That can mess with the manifold pressure readings.

Vacuum leaks, huh? Where should I be looking specifically? Is there a common spot on these that tends to fail?

On mine, it turned out to be a cracked hose connected to the intake manifold. A large vacuum leak will definitely throw off the MAP sensor readings. Honestly, with those symptoms, and without specialized equipment to properly diagnose a faulty MAP sensor, I would take it to a workshop.

Thanks for the tip! Took it to the shop, and you were right – a large vacuum leak was the culprit, messing with the manifold pressure sensor. They replaced a cracked hose, and everything's back to normal now. Cost me 235€, but worth it. Appreciate the help!