Volvo post 1999 Marelli electronic throttle system (also known as ETS, or throttle body).
Symptoms: intermittent rough idle, no power, car goes into limp home mode. Can bring on the Engine Management and/or ETS light, but sometimes does not. Will sometimes correct itself after cycling the ignition, but re-occurs soon.
BBA can remanufacture these units. A software update called the “ETM Reload” is required when installing back in the vehicle; this update must be done by a Volvo dealer! Call for price and availablility.