Yes,It is possible that your engine could temporarily decrease in mileage and increase in emissions after the initial installation. This would be due to poor maintenance, excessive carbon build-up, and is temporary. The Fuel Saver will eventually stabilize the system.
In vehicles that do not have computer control of the idle speed, the idle can increase by as much as 500RPM. If this occurs, please ask your mechanic to reduce the idle speed or you will not save fuel in traffic.
Ensure the Greentech Fuel Efficiency Technology makes contact with the fuel. We have found that shortcuts have been taken during installation by dropping the Fuel Efficiency Technology sensor down the filler neck. If a filter or anti-siphon device is fitted into the filler neck, the Fuel Efficiency Technology sensor will not enter the fuel tank, and the fuel will not be treated.
Ensure the engine is well serviced and the engine oil is in good condition. Change the engine oil if necessary.
Any mechanical problem with the engine, in particular the fuel or lubrication system, will cause the Fuel Efficiency Technology to be ineffective.