An apparatus for modifying sensor signals provided to an engine control unit in a vehicle, the sensor signals including at least a fuel pressure signal, wherein the sensor signals are generated by a plurality of vehicle sensors including at least a fuel pressure sensor, each sensor signal comprising a sensor signal value that is indicative of an operational characteristic of an engine in the vehicle, and the engine control unit is configured to receive the sensor signals and generate engine control signals based at least in part on the sensor signals, the apparatus comprising: a fuel composition sensor that senses characteristics of fuel in the vehicle and generates a fuel composition signal based on the sensed characteristics, wherein the fuel composition signal is indicative of a ratio of alcohol to gasoline in an alcohol/gasoline fuel blend, a fuel control module that intercepts the sensor signals from the plurality of vehicle sensors, the fuel control module including a processor programmed to generate modified sensor signals based at least in part on the intercepted sensor signals and the ratio of alcohol to gasoline in the alcohol/gasoline fuel blend as indicated by the fuel composition signal, wherein the modified sensor signals comprise sensor values that the processor generates by adding to or subtracting from corresponding measured sensor values, the modified sensor signals including at least a modified fuel pressure signal indicating: - a fuel pressure value that is lower than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is greater than an alcohol percentage setpoint programmed into the engine control unit, or - a fuel pressure value that is higher than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is less than said alcohol percentage setpoint programmed into the engine control unit, and wherein the modified sensor signals are provided to the engine control unit in place of the intercepted sensor signals from the plurality of vehicle sensors. a fuel composition sensor that senses characteristics of fuel in the vehicle and generates a fuel composition signal based on the sensed characteristics, wherein the fuel composition signal is indicative of a ratio of alcohol to gasoline in an alcohol/gasoline fuel blend, a fuel control module that intercepts the sensor signals from the plurality of vehicle sensors, the fuel control module including a processor programmed to generate modified sensor signals based at least in part on the intercepted sensor signals and the ratio of alcohol to gasoline in the alcohol/gasoline fuel blend as indicated by the fuel composition signal, wherein the modified sensor signals comprise sensor values that the processor generates by adding to or subtracting from corresponding measured sensor values, the modified sensor signals including at least a modified fuel pressure signal indicating: - a fuel pressure value that is lower than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is greater than an alcohol percentage setpoint programmed into the engine control unit, or - a fuel pressure value that is higher than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is less than said alcohol percentage setpoint programmed into the engine control unit, and - a fuel pressure value that is lower than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is greater than an alcohol percentage setpoint programmed into the engine control unit, or - a fuel pressure value that is higher than the measured fuel pressure if the percent alcohol in the gasoline/alcohol blend sensed by the fuel composition sensor is less than said alcohol percentage setpoint programmed into the engine control unit, and wherein the modified sensor signals are provided to the engine control unit in place of the intercepted sensor signals from the plurality of vehicle sensors.