If like me you have spent the winter doing mainly short journey’s, you may have started to notice an effect on engine performance. I started to get a little overboost at low speeds so decided to look at all the options. The guaranteed solution was remove the turbo, strip and clean. If you don’t do it yourself, you are looking at £800-900 pounds. The alternative is chemical treatment with the turbo in-situ. Fortunately someone else had reviewed fuel additives and posted their experiences and conclusions. HHO cleaning is a nonsense in my opinion (I have a PhD in Chemistry) so I took an educated punt at the Forte system. The garage checked the engine over and removed and checked all the turbo hoses before proceeding. Post cleaning what a difference-it is like driving a different car. Turbo pickup is instant and it accelerates smoothly through the rev range. The engine is quieter and much more refined. Although expensive at £180, in my experience well worth the money. Although I wasn’t getting any fault codes, the turbo and engine were clearly not working as they should.

That's a fair comment but your turbo must not have been that bad.
If you have a chemistry PhD you could have checked the chemical make up of the oven cleaned. Essentially it is designed to loosen and or dissolve carbon deposits. Carbon deposits are what causes the variable geometry part of your turbo from working correctly. Resulting in over boost and under boost problems depending on the position of the stuck disc. Dissolve the carbon deposits and the disc will move freely returning the turbo to full operating performance. Now at the point when I learn something new something old is lost out the other side !
Now retired so it doesn't matter anymore.
Freelander now gone.

Oven cleaner is slightly different. The active ingredient in most of the more effective ones is sodium hydroxide. You apply it cold. I don’t truthfully know how the Forte system works or if it uses HHO technology. What I do know is that HHO is a nonsense. You are essentially feeding Hydrogen and Oxygen into your engine. Apply heat and the mixture goes bang with water (H2O) and Hydrogen Peroxide (H2O2) being formed together with a lot of heat. Hydrogen Peroxide is thermally unstable so will almost immediately break down leaving water. So HHO is actually H2O. The inside of the engine is essentially steam cleaned. I think you are probably right-my engine was fairly clean. I was experiencing sticking vanes and sluggish performance but it didn’t ever throw fault codes. The difference in performance, however, is amazing. I have a couple of steep hills on the way to work. Before the clean, the auto box always dropped a cog from fifth to fourth. This morning it held fifth and kept accelerating. I was and still am a little skeptical about the effectiveness of these engine cleaners, but I can’t argue with the effect it has had on my engine.

Sounds like £180 well spent if it improved things that much. Jules