The BLOX Racing MAP Bypass Valve is designed for use with forced-induction applications.The MAP Bypass Valve completely blocks boost from reaching the MAP sensor, thus simulating a wide-open-throttle reading at the vehicle's ECU. The vehicle is then prevented from running in "limp" mode so that no check-engine light appears. The end result is protecting the MAP sensor from being damaged.MAP Bypass Valves are vailable as internal or external units.