Ethanol content sensor for use when E85 fuel is being used. E85 fuel varies greatly on ethanol content from one fueling station to the next. On vehicles running E85 fuel, this causes lots of problems as the ethanol content of the fuel plays a significant role in the tuning needs. By installing an enthanol content sensor, you can monitor ethanol level content and use this information to apply changes to your tune.

The sensor should be installed in the fuel return line. Ideally, after the fuel pressure regulator in the return line to the fuel tank.