This device is to modify the Oxygen (O2) sensors signal in fuel injected vehicles. EFIEs are the best solution for obtaining improved fuel efficiency in computer controlled vehicles with oxygen sensors.
If all you did was add an EFIE to your car, with no other fuel efficiency system, you may actually lose some efficiency. You might even damage your car, by over-leaning the fuel/air ratio, and overheating the valves. The EFIE was designed to make the car run according to spec after another fuel efficiency device has been installed.
With no modifications other than HHO, performance increase and smoother idle are immediate. However, when installing an HHO cell in a newer car more has be done to achieve significant mileage increases. After we introduce HHO gas the oxygen sensor reports a change in the exhaust gas makeup to the computer. The computer in turn tries to correct the perceived problem by dumping in extra fuel. This state usually turns on your check engine light, sets fault codes and puts the computer in a state called open loop. In open loop the computer stops modifying the fuel ratios and reverts to a “safe” mode. Safe mode dumps extra fuel. This can reduce the mileage benefits dramatically.
The EFIE will get us back to closed loop by adjusting the signal to the computer, thus allowing the correct adjustments for various driving conditions to be made. Basically, the oxygen sensor tells the computer it's oxygen readings by providing a voltage between 0 and 1 volt. In order to adjust this "data" the EFIE adds a small voltage to that delivered by the oxygen sensor. This added voltage compensates for the variation caused by HHO. This EFIE is highly adjustable. Adjustments to the trim screw can change the EFIE's voltage correction by tiny amounts; a millivolt or 2 (.001 volt).
This can be done on a much more basic level by adding an oxygen sensor spacer or two. The O2 spacer pulls the sensor out of the exhaust gas flow, making it less sensitive, and causing the computer to lean the fuel mixture. The spacers are a mechanical solution and therefore not adjustable, some have great results, some not much. O2 spacers are cheap, easy to install, and fit many vehicles. Don’t buy spacers without metal gaskets, they may not seal properly. Spacers with tapered sides may wedge in your exhaust and become unremovable.
This EFIE (Electronic Fuel Injection Enhancer) circuit board will modify the O2 sensor signal, and is adjustable. This circuit board installs inline between the oxygen sensor and computer. This device requires a higher degree of skill and automotive knowledge to install. An EFIE board will be required for each precatalytic converter sensor. There are single boards for vehicles with one precat O2 sensor and dual boards for vehicles with two precat O2 sensors. Some vehicles have more than two precat sensors; in these cases more than one board will be necessary. Some vehicles now utilize a new kind of exhaust sensor referred to as a wideband or AFR. These sensors began appearing around 2000. A narrow band EFIE will NOT properly adjust a wide band signal. A narrow band o2 sensor operates on a change in voltage and a wide band sensor uses amperage to relay its signal.
