Punto check engine light reduced power

A check engine light combined with reduced power and increased fuel consumption? That combination is rarely a good sign. Have you observed any unusual noises, such as a compressor surge, coming from the engine? Perhaps a faulty pressure sensor on the intake manifold giving false readings due to a vacuum leak?

No unusual noises that I can hear. Where exactly is the pressure sensor located, and how would I check for a vacuum leak myself?

Given that you’re not hearing any unusual noises, the compressor itself is most likely sound. Diagnosing a vacuum leak without specialist equipment can be tricky. I would advise caution, because fiddling with the engine components may cause further damage. I highly recommend going to a trusted workshop and having them perform a dedicated diagnostic and possibly a smoke test to pinpoint the issue.

Thanks, I appreciate the advice. I took it to a workshop, and it turned out to be a defect in a vacuum switching valve, as suspected. Repair cost was 140€. Runs like new now!