Has anyone done an installation on a seat inca similar to the volkswagen caddy? I have a hho install done but so far mpg has gone down. The unit produces a relatively high level of mono atomic hydrgen, the manufacturer recommends 130 to 150 mls of hho gas per litre of engine displacement per minute. The van doesn't have an oxygen sensor and very basic ECU. Would appreciate any input from some knowledgeable hho person. The van normally does 50 miles per UK gallon, it has a 1.9 diesel engine and its 1998. Thanks in advance.