Almost all modern vehicles, either fuel injected or carbureted, employ oxygen sensors to tell the vehicle's computer if the air/fuel mixture is too rich or too lean.
The computer uses the information from the 02 sensor to determine if more or less fuel should be added to the mix in order to maintain the correct proportion.

Most vehicles are designed to operate at an air/fuel ratio of 14.7 to 1. When these proportions are being supplied to the engine, a certain amount of oxygen will be detected in the exhaust by the 02 sensor, and this information is fed into the vehicle's computer.

If more oxygen is sensed, the computer thinks the mixture is too lean (not enough fuel), and adds fuel to the mix. Likewise, if less oxygen is sensed, the computer thinks the mixture is too rich (too much fuel) and cuts back on the fuel fed to the engine.

This is actually an artificial relationship, but has been found to be workable with the existing techniques of burning fuel in your car's engine.

There's a big problem with this scenario since, as soon as you start adding a workable fuel efficiency device like a hydrogen booster, the oxygen content in the exhaust will rise.

If you have two or more efficiency devices installed, even more oxygen will be present in the exhaust. The oxygen content rises as the fuel is burned more efficiently for a number of reasons. Chief amongst these are.....

(1) less fuel is being used to produce an equivalent amount of horsepower, and

(2) less oxygen is being consumed to create carbon monoxide in the exhaust.

The bottom line is there is more oxygen in the exhaust as the fuel burning efficiency is increased.

So, now that we have spent time and money to install a fuel efficiency device or two and we are getting a more efficient fuel burn, what does the vehicle's computer do? It dumps gas into the mix in an attempt to get an oxygen reading in the exhaust equal to it's earlier, inefficient setup. This will then negate the fuel savings of just about any efficiency device, and in some cases will actually cause an increase in fuel consumption, despite having a workable fuel efficiency device.

The Solution is simple

The signal coming from the 02 sensor needs to be adjusted to compensate for the increased fuel efficiency being achieved.

Basically, we need to fool the computer into thinking that the engine is still burning gas inefficiently, by making it think there is less oxygen in the exhaust than there actually is.

The amount of change to the signal is easily adjustable to accommodate different amounts of efficiency increase from different size hydrogen boosters.

It should be noted that an oxygen sensor handling device (EFIE) by itself, is not a fuel efficiency device. The EFIE could be used to control the vehicle's computer and make the engine burn a little leaner and this would give a small increase in gas mileage. But this is not what it was designed to do.
It was designed to complement, and in some cases make possible an increase in gas mileage using other fuel efficiency devices such as a hydrogen booster.

Complete Installation
Instructions

Updated-5-30-08

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Simple Instructions

Cut one wire to the O2 sensor, attach the green wire to the O2 sensor and the white wire to the computer. Connect the red and black wire to a switched power source. Turn on power and
Set the output to .25 -.3 volts with a VOM connected to the white and green wire.

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There are two adjustments on the EFIE
You only need to use the voltage adjuster not the Range Adjustment

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(1) Locate the oxygen sensor signal wire

The easy way to do this is to look it up in your Haynes, Clymer or Chilton manual for your car. OR, if you don't have one of these, there is a service at www.ahdol.com where you can pay a nominal fee, and get your wiring diagrams emailed to you.

We have also recently found a resource at www.autozone.com whereby you can get your wiring diagram on your sensors.

* Locate your car, year, make and model.
* Select "Repair Info" at the left side of the screen.
* Then select, "Vehicle Repair Guides"
* then > Chassis Electrical > Wiring Diagrams

The information is not available for all cars and trucks.

Unfortunately, the sensor can have 2, 3 or 4 wires, and you have to know which one is the signal wire. If you have 4 wires they will be:

1. Heater 12 Volts +
2. Heater ground
3. Oxygen sensor signal +
4. Oxygen sensor signal ground

If you have 2 or 3 wires, then you can have a common ground, or no heater wires etc.

The simplest setup is a one wire O2 sensor, which is the signal wire. The O2 sensor gets it's ground from the exhaust pipe. But you would still use the following procedure to narrow down which wire is which:

Disconnect the wire harness to the O2 sensor.
Turn on the ignition.
Probe for 2 wires that produce 12 volts between them.
This will be the heater circuit and ground.
The two wires left will be the sensor signal and the ground.

Reconnect the wiring harness, then strip a little insulation off each of these wires and measure them with the engine running.

When you have found the right wire you should get voltage reading that is constantly fluctuating between 0 and 1 volt (.35-.65 volts is common).

If the readings are negative, reverse your probes.

Now the positive probe will be the signal wire you've been looking for. Cut this wire at a convenient location for connecting the EFIE.

We'll call the sensor side of this cut wire the sensor wire, and the other side of the cut, the computer wire.

Note: rarely an oxygen sensor wiring harness will have more than 4 wires. In this case, the sensor is possibly a "wide band" oxygen sensor.

The EFIE is not designed to work with all wide band sensors, although some wide band sensors have an interpreter that gives out a narrow band signal before routing to the computer.

Now that you have determined which is the sensor's signal wire, you can make the connections close to the computer. If you used a manual or wiring diagram, you probably have already located the wire at the computer's wiring harness. If you had to figure out the wires at the sensor itself, then try to find the same wire at the computer's wiring harness. It should be the same colors, but test it with an ohm meter to be sure or just make the connection under the hood.

It's worth it to get the signal wire located up by the computer. This makes cutting into and hooking up the EFIE much easier, especially if you are mounting the EFIE inside the cab.

(2) Locate 12 volt power and ground

You need to ensure that you have switched power, not power directly from the battery.

Note:
When power is shut off to the EFIE, or the power switch is turned off, the original connection between the oxygen sensor and the computer is re-established.

This will allow the EFIE to be turned off and on with your hydrogen booster if so desired. Simply connect the red wire to the VOC (not shown here).

If connecting to your hydrogen booster is inconvenient, just use any circuit that is accessory key switched.

Your electrical diagram can come in handy here, and if you don't find another device to attach to, you can usually find a spare circuit in the fuse box (you may have to add a fuse).

One installer used the oxygen sensor's heater power for his EFIE's power, and this is perfectly acceptable.

Note:

1. This EFIE is not waterproof. If you mount it under the hood, you will have to take care to cover it if you need to steam clean your engine. You may want to mount the EFIE in the passenger compartment where it will be protected.

2. If you live in a very cold climate, where temperatures are expected to be below freezing for a significant number of days per year, you will want to ensure that the EFIE is mounted where it will be warmed, either by the engine, or inside the passenger compartment or move the jumpers J1 and J2 to the heating position.

4. Attach the wires

Connect the red to your power source.
Connect the black to ground.
Connect the green wire to the oxygen sensor.
Connect the white wire to the computer.

You should solder them and use heat shrink tubing to insulate the connections from other wires. If you don't have heat shrink, you can use electrical tape.

Important Note:

Take care to not reverse the connections for the red and black wires as the EFIE will burn out!!! It will make smoke and will smell bad...(;;) If this happens, the unit can be fully restored by merely replacing the voltage regulator. Contact us for a new regulator if this occurs.

EFIE Connection Diagram