EFIE basics

Fuel Injection and EFIE Basics

Fuel injected vehicles use an onboard computer and electronic sensing devices to monitor and maintain the correct air/fuel ratio for engine combustion. One of the key sensing devices is the oxygen sensor. Fuel injected vehicles have one or more oxygen sensors installed in line with the exhaust exhaust system. The computer calculates what the air/fuel ratio is based on the amount of oxygen that the oxygen sensor(s) report is in the exhaust.

When a fuel saving device is installed, such as a hydroxy electrolyzer (HHO gas generator), the petroleum based fuel is burned much more completely. One of the results of this is that there is more oxygen (and less unburned fuel hydrocarbons) in the exhaust stream. This is a good thing, and exactly what we are trying to achieve by adding an HHO system. But the computer will interpret this condition as a "too lean" air/fuel mix. In other words, what is now a desirable condition in the exhaust, will be interpreted as "not enough gas", and the computer will direct the fuel injectors to dump more gas into the engine.

The result is that the oxygen sensor and computer prevent efficient combustion from occurring! And without intervention on our part, this will actually deteriorate a vehicle's mpg and performance.

The Solution

The oxygen sensor "tells" the computer what the oxygen content is by providing a voltage on it's signal wire between 0 and 1 volt. 450 millivolts (.45 volts) means that the fuel/air mixture is correct. Higher values means the mix is rich (has too much gas), and lower voltages means the mix is lean. By adding voltage to the sensor's output, we can compensate for the additional oxygen in the exhaust.

An Electronic Fuel Injection Enhancer (EFIE) does exactly this. It adds a floating voltage to the top of whatever the oxygen sensor is putting out. It has an adjustment that allows you to control, to within a few millivolts, the amount of this added voltage. This function of the electronic fuel injection ehancer (EFIE) effectively prevents the computer from sensing the additional oxygen content of the exhaust, and the HHO generator system can now achieve it's full potential in fuel savings.

Most cars have oxygen sensors both before and after the catalytic converter. The ones behind, or downstream from the converter do not need to be modified with an EFIE. Their purpose of their data readings is used to determine is or when the catalytic converter has gone bad. They are not used in the air/fuel calculations. EFIEs are only needed for the oxygen sensors between the engine and the Catalytic converter - Just the 'upstream' O2 sensors need treatment.

If you are purchasing an HHO electrolyzer for a fuel injected vehicle, you will need to also install an EFIE (single or dual) for your HHO system to perform properly and to realize the gas mileage and performance boost.