I had a problem in my car "Opel" regarding Fuel Injector cleaner, and i was told that it applies to all injection systems...
I put a fuel injector cleaner "FIC" of a reliable brand in my tank, filled it to top, and speeded into 80mph for 30 min... the result was not as good as i wanted and the car ended up being pulled to the garage!
i had to change many parts in the injection system as they were clogged with black smudge that didnt come off with regular solvents... the mech told me later that the FIC really cleans smudge OFF the fuel tank, take it "dissolved" into fuel filter "as petrol mixed with dissolved debris" as the filter gets clogged, the mixture is passed right into the injectors,, speeding up causes engine to heat up, and the fuel starts to leave the debris in the burning chamber and around the valve outlets, making fuel mixture face more pressure as it enters the combustion chamber, this make the engine rpm require more gas -to reach certain values- than it used to,, and eventually check engine light comes on!! the bes thing to do with FIC is to apply it diluted in a full tank just after cleaning or replacing the fuel filter and cleaning the valves, otherwise it will only take all the rubbish in tank, and pour em into the suffering engine!!
Hope this peace of info is helpful..
Good luck