Will vehicle ajdjust on own??

I have read a lot about the electrical control mods that are needed to make the HHO generator work with any vehicle, my question is this. I was under the impression the vehicle, whatever make/model would notice the introduction of HHO into the engine, via O2 sensors in the exhaust, then automatically cut back fuel at the injectors to compensate....this is how I first understood it. Now I see all this stuff aout mapp controlers and resistors inline with the O2 sensors. Is all this even needed? Why wont the vehicle do it automatically? making the Generator is a cakewalk for me, I just need to know what type of stuff needs to be done to the electrical control area to make this work. Vehicle in question will be a 2001 Tacoma, 3.4 NA V6, then possible a 2004 Civic thanks for the help

Tom

sure about those particular vehicles, but the o2 sensor(s) are going to notice that the exhaust is more oxygen rich aka lean, so it will send back voltage indicating a lean condition to the engine computer, which will then actually increase the amount of fuel to compensate and bring it back to "safe" levels (safe being the operative word because most engines can take a leaner condition than what the manufacturer programs it for, it's more of an emissions fix to run the engine richer, from my experience). It's similar to my experience with turbo engines and having to fool the MAP sensor to think that it is not exceeding it's read limit when it really is. (I.E. pressures of 14.7 on a chrysler stock T1 setup....)

-hooty

my car is getting 50% better milage sence i added my hho cell but my check engen light has been on for a long time "even before i put the cell on" the code comes uo cam shaft senser. i put a timeing light on the car and my timeing is 40deg advanced this may have something to do with it..