BG Findashop - Fuel/Air Induction Service: "Intake valve with heavy deposit build-up. Intake valve after service.
The Exhaust Gas Recirculation (EGR) valve is clogged causing loss of power. If neglected a costly repair bill is imminent.
Remove EGR valve and attach a specialized tool at the EGR port, where a carbon-attacking chemical eliminates carbon build-up."