What do fuel ionizers and fuel catalysts claim to do?

• minimize fuel flow using ionic fields
  A variety of devices claim that they use ionic charges or catalytic action to alter fuel into a more efficient form. An equal variety of reasons, from onboard engine computer adjustments to basic chemistry, make these claims dubious at best.
• dissolve smog-producing agents in fuel
  A variety of devices claim that they use ionic charges or catalytic action to alter fuel into a more efficient form. An equal variety of reasons, from onboard engine computer adjustments to basic chemistry, make these claims dubious at best.
• alter fuel to make it burn more efficiently
  A variety of devices claim that they use ionic charges or catalytic action to alter fuel into a more efficient form. An equal variety of reasons, from onboard engine computer adjustments to basic chemistry, make these claims dubious at best.