Intelligent Fuel Trimmer (IFT) is an intermediate electronic module that deploys in between OEM Engine Control Unit (ECU) and fuel injectors of an automobile. The function of this module is to modify (Amplify or Attenuate) the OEM ECU injector pulse width for each of the four PWM signals which control the fuel injectors. In simple words this device manipulates the amount of injected fuel. It makes the engine more fuel efficient and allows it to run on different fuel mixtures. An implementation result proves the functionality of the designed module in automobile.