Another product I always use when I change my car, along with a new K&N air filter. I know many people are sceptical about using fuel additives, however, when the top car manufacturers (BMW, Toyota etc) use this product as a fuel system and engine cleaner, at service, it speaks volumes. At one time, a coked up engine needed cylinder head removal, and physical cleaning away of all the coke. I have done a few in my time. This however does the same without even opening a toolbox! Just open the fuel filler cap, pour and then fill up with fuel. Drive until quarter full, and refill again.
I know the likes of Redex etc has been used in the past, and yes it can help, but is very limited. This however, does what it says on the Can. Just make sure you use on short runs though, as it works better like this. It seems that it has more time to work its stuff!
Just note though, that if you are having trouble with a Turbo diesel and EGR valve malfunction, a new product, made by FORTE (diesel turbo and egr cleaner) is getting great reviews. That seems to be the only product on the market at the moment, that targets the Turbo and EGR valves!