I have learned that the computer measures the oxygen levels and adjusts the amount of gasoline to put in the engine with those sensors. Since I am pumping HHO, with is extra oxygen, the computer thinks they gasoline to air ratio is too rich in oxygen and dumps more gasoline in the system. So, that explains my results:
27 mpg with just baking soda
23 mpg with NaOH (1 tsp. drain cleaner), a better catalyst and did produce more HHO gas.

Normally I average 30 mpg.

Today I unplugged the O2 sensor on the front of the engine to see if there's a cheap way to trick the system. I suspect I will need to install the MAP sensor to trick the computer correctly.

Getting Started

The basic concept is to have water in a container produce HHO by adding a power to the water, then pumping the HHO in to the air intake of your car.














I had to reinforce the seals on the HHO generator as it was leaking water out the top and the bottom. I don't think the treading was done correctly. I almost filled the container with distilled water and a teaspoon of baking soda.

I connected the power by splitting the power from the left front headlight as I thought this would be a convient switch. I also put a switch just above the HHO generator. The HHO gas exits the generator and was inserted by putting a T on a hose going from the engine block to the air intake hose (before the fuel injector and after the air filter).
I've read and it makes sense that this can increase your fuel effeceincy by 10%-50%. That makes sense. I will install the MAP sensor to lean my fuel after I get a calculation of the MPG on this first. I doubt I will get any MPG improvements yet, though I've heard people do.