Toro Diesel Reduced Engine Power

That sounds familiar. I had almost identical symptoms on my old Volvo V70, although it was a gasoline engine. The check engine light illuminated, and it felt like the engine was constantly fighting itself. Reduced power, stumbling acceleration. The computer was throwing codes related to mixture. Have you checked the throttle body for carbon buildup? Also, have you looked at the intake manifold for any leaks or cracks? A rich mixture can also damage the catalytic converter, leading to other problems.

Throttle body and intake manifold are good ideas. I hadn't considered those specifically. Did your Volvo issue stem from the fuel injectors? If not, what was the cause? I'm trying to narrow down the possibilities before tearing things apart or spending a fortune.

It wasn't the injectors directly, but rather a faulty sensor that was misreporting the air/fuel mixture. It was like the car's brain was getting bad information, so it was making incorrect adjustments. Given your symptoms and the potential for injector issues in diesels, it might be a good idea to get it checked out by a workshop with the right diagnostic tools. They can often pinpoint the exact problem much faster than poking around, and it could save you money. A mechanic confirmed that the injector was defective and recommended replacing it.

Based on your experience and the mechanic's assessment, I decided to take it to a professional. It turned out to be a defective injector, as suspected. The repair cost me around 515€, but the car is running smoothly again. I appreciate your help in steering me in the right direction!