Radium Split Flow Flex Fuel Sensor AdaptorFlex fuel sensors measure ethanol content. They can be used in the FPR return line. But for improved accuracy and faster response times, the sensor should be plumbed upstream of the fuel injectors in the feed line. In this case, expect to see up to a ~10psi pressure drop if multiple pumps are used with a high powered engine. The Radium Engineering adapter splits the fuel flow into an auxiliary passage parallel to the sensor. Because the flex fuel