This^^^
When these so-called "octane boosters" you can buy OTC say that they raise the octane rating by "4-7 points", what they really mean is 4 to 7 TENTHS. Using one as directed will raise the octane of 87 fuel to 87.7 max.
Do as advised above and use 91 (or higher).
As for fuel injector cleaners, try to find Regane (by Gumout) or Techron (by Chevron). These contain PEA (polyetheramine) and are generally recognised as safe and effective. No need to use it more than a couple of times a year.