S60 Faulty Injection System Symptoms

Man, those symptoms sound rough! I had something similar happen with my S60, though I can't remember the exact year. Higher fuel consumption and reduced engine power ring a bell big time. Did you check for any leaks around the fuel injectors? That can mess with your fuel-air mixture and cause all sorts of problems. And have you tried cleaning the mass airflow sensor? That sometimes causes rough idling and loss of power too.

Thanks for the quick reply! Fuel leaks, huh? I haven't specifically checked for those... where exactly should I be looking? And the mass airflow sensor, is that easy to get to? I'm not super mechanically inclined, but I can usually follow instructions. Is it easy to damage the mass airflow sensor if I'm not careful?

Yeah, fuel leaks can be tricky, but check around the fuel rail and where the injectors connect to the engine. If you smell gas, that's a pretty good sign. As for the mass airflow sensor, it's usually right after the air filter box. It's not hard to get to, but be gentle! Use a special MAF sensor cleaner; don't just spray it with anything. Honestly, with all those symptoms, you might want to get it checked by a pro. It could save you a lot of headaches.

Okay, awesome. I really appreciate the advice. I think you're right, it's probably best to just take it to a workshop before I make things worse. It was a defective cable or plug connection of the component. All sorted now, cost me 95€. Thanks again!