OT Kinda..but do those STP gas additives really do anything?
Only after many repeated uses.
Through the years I have tried just about every imaginable fuel injector cleaner on the market.(On customer's cars ofcourse

).
Chevron Techron is the only one I know that does the job with one cleaning.
Warning
DO NOT spill it on you or your vehicle,It WILL cause extensive nervous system damage and is a very effective paint remover as well.
If you do use Techron,Poor it in an empty tank
at the gas station then fill the tank.
DO NOT just poor it in without filling the tank,the undiluted Techron will eat fuel injector lines,pressure regulators etc.