Full transparency: I do own Chevron stock. But I've also done lots of tests with it. Yes "Concentrate" is the thing to get. It has a high dose of polyether amine. That's a fancy way of describing its designer molecule. One end of the molecule, the "amine" part (in the same chemical functional family as ammonia) is "polar" and is attracted to metal surfaces, deposits, and things that might form deposits. The other end is the "polyether" part that is wonderfully soluble in gasoline. So, the polar end attaches to stuff, and the tail is carried to and from anywhere gasoline splashes. So it cleans deposits and things that might form deposits and also protects metal surfaces from those deposits.
On top of that, the polyether part burns very cleanly so there is no residue left behind. In fact it removes deposits left behind by other lesser detergents.
There is also lots of "no harm" testing done with it on taxi fleets and so on. It cleans deposits and doesn't hurt other things. So it's strong but gentle.
Techron is the one that is consistently strong. Other brands pop up now and then, some are good, while others have nothing except a carrier oil and a little solvent. Some even change, depending on who is in charge of marketing a given year.
Many car companies also endorse Techron in one way or another. I used to keep a list and still probably have it somewhere.
Wow, I sound like a marketing guy! :-)
Try a bottle or two or three and run a couple of tanks of gas. If you use three then probably change your oil after that because trace amounts of any detergent wind up in the crank case and you don't want to disturb the additive package in the oil. One is no problem at all, but with three you might want to change it. If that doesn't take care of your injectors then look into one of the other products that uses a super nasty solvent and isolates the injector rail. You don't want that super nasty solvent circulating through your whole fuel system. Harbor Freight used to have a DIY apparatus to hold and pressurize the solvents and deliver them to your isolated fuel rail, but not sure if they do now.
I see Walmart online carries the OTC tool $144 with free shipping:
https://www.walmart.com/ip/OTC-Tools...BoC_uIQAvD_BwE
But I'd try the Techron first.
Good luck and please keep us posted.