APPLICABLE TO 5,6-WIRE WIDEBAND SENSORS ONLY. Magnum EFIE has been developed to engines installed with popular water4gas generators. It modifies the Oxygen Sensor signal in fuel injected vehicles controlled by ECU. When installing an H2O electrolyzer more should be processed to achieve extreme MPG increases. After we inject HHO gas into the engine the oxygen sensor reports a change in the exhaust gas consistence to the Electronic Control Unit accordingly ECU will fix the perceived problem by enriching the mixture. This situation will indicate usually an error code turning on the check engine light and put the ECU in open loop status with medium level performance. Safe mode dramatically decreases MPG benefits resulted by H2O generator. EFIE is not intended to be a fuel saver by itself but can warrant good MPG if you use HHO. If you install a HHO system the oxygen content in the exhaust will rise. The more powerful HHO kit you apply the more oxygen will be in the exhaust gas & this will result a fuel lean status accordingly ECU will send more fuel thus actually you will not save fuel despite this was the main goal to convert to HHO hybrid. We need to trick ECU into thinking the engine is still burning inefficient within the combustion chamber, by fooling the computer to sense there is less oxygen in the exhaust than there actually is. The mount of modification to the voltage signal is simply adjustable thru the enhancer to accommodate different amounts of HHO being injected. EFIE adjuster wires inline between the oxygen sensor & ECU. Even people who are not technical minded will find, EFIE is not difficult to install just needs 20 minutes. ALL CONNECTORS INCLUDED. * * * * 10-YEAR MAGNUM FACTORY WARRANTY * * * * Magnum TuningTM has been dealing with manufacture of upgrades and fuel saver parts since 1994. Magnum's experience warrants peak performance, reliability & perfect style. Magnum Parts are made in EUROPE.