Most modern Petrol engines, and pretty much all Diesel engines are direct injection, which although great for effieciency, it does cause an underlying issue with carbon build up in the inlet ports.
As no fuel is flowing through the inlet to keep it clean, all direct injection engines will sooner or later have restriced inlet ports, poor running, low power caused by carbon build up.
The way to remove this carbon, is remove the inlet, and fire high speed crushed walnut shell in to the port using special tooling.
This is a process we can carry out in house.
Prices from £250.00