Original Engine Management MS21 Map Sensor Fuel Tank Pressure Sensors ensure EPA and CARB compliance on OBD2 vehicles. If the evaporative emissions systems has a leak or the vehicle's gas cap is loose, the sensor is calibrated to command the PCM to illuminate the CEL alerting driver of issue. Manufactured to OE specification for fit, form, and function Heavy-duty thermoplastic housing Precison-engineered circuit for faster response time