The former typically involves (or at least should, if done correctly) hooking up a bottle of cleaner to the engine’s fuel-injector rail, shutting off the fuel pump by removing either the fuel ...

Fuel injectors can get gummed up with dirt and fuel residue over time. Photo credit: David Traver Adolphus / Autoguide.com.

CNET’s expert staff reviews and rates dozens of new products and services each month, building on more than a quarter century of expertise. Fuel injector cleaner serves an important function in ...